diff --git a/rocrate_validator/profiles/five-safes-crate/must/6_workflow_reference.ttl b/rocrate_validator/profiles/five-safes-crate/must/6_workflow_reference.ttl
new file mode 100644
index 00000000..ded22942
--- /dev/null
+++ b/rocrate_validator/profiles/five-safes-crate/must/6_workflow_reference.ttl
@@ -0,0 +1,71 @@
+# Copyright (c) 2025 eScience Lab, The University of Manchester
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+@prefix ro: <./> .
+@prefix ro-crate: <https://github.com/crs4/rocrate-validator/profiles/ro-crate/> .
+@prefix five-safes-crate: <https://github.com/eScienceLab/rocrate-validator/profiles/five-safes-crate/> .
+@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix schema: <http://schema.org/> .
+@prefix purl: <http://purl.org/dc/terms/> .
+@prefix sh: <http://www.w3.org/ns/shacl#> .
+@prefix validator: <https://github.com/crs4/rocrate-validator/> .
+@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+
+
+
+five-safes-crate:ReferenceToWorkflowCrate
+    a sh:NodeShape ;
+    sh:name "RootDataEntity" ;
+    sh:targetClass ro-crate:RootDataEntity ;
+
+    # RootDataEntity MUST have an mainEntity property
+    sh:property [
+        a sh:PropertyShape ;
+        sh:name "mainEntity" ;
+        sh:path schema:mainEntity ;
+        sh:minCount 1 ;
+        sh:maxCount 1 ;
+        sh:nodeKind sh:IRI ;
+        sh:severity sh:Violation ;
+        sh:message "The RootDataEntity MUST have exactly one schema:mainEntity property that is an IRI." ;
+    ] ;
+
+    # The mainEntity of a RootDataEntity MUST be a Dataset
+    sh:property [
+        a sh:PropertyShape ;
+        sh:name "mainEntity" ;
+        sh:path schema:mainEntity ;
+        sh:class schema:Dataset ;
+        sh:severity sh:Violation ;
+        sh:message "The mainEntity pointed to by the RootDataEntity MUST be of type schema:Dataset" ;
+    ] .
+
+five-safes-crate:mainEntityHasProperConformsTo
+    a sh:NodeShape ;
+    sh:name "mainEntity" ;
+    sh:description "The mainEntity of the RootDataEntity MUST have a conformsTo property with an IRI starting with https://w3id.org/workflowhub/workflow-ro-crate" ;
+    sh:targetObjectsOf schema:mainEntity ;
+    sh:sparql [
+        a sh:SPARQLConstraint ;
+        sh:name "conformsTo" ;
+        sh:message "conformsTo IRI must start with https://w3id.org/workflowhub/workflow-ro-crate" ;
+        sh:select """
+        PREFIX schema: <http://schema.org/>
+        PREFIX purl: <http://purl.org/dc/terms/>
+        SELECT $this WHERE {
+            $this purl:conformsTo ?iri .
+            FILTER(!STRSTARTS(STR(?iri), "https://w3id.org/workflowhub/workflow-ro-crate"))
+        }
+        """ ;
+    ] .
diff --git a/rocrate_validator/profiles/five-safes-crate/should/6_workflow_reference.ttl b/rocrate_validator/profiles/five-safes-crate/should/6_workflow_reference.ttl
new file mode 100644
index 00000000..c7690ae0
--- /dev/null
+++ b/rocrate_validator/profiles/five-safes-crate/should/6_workflow_reference.ttl
@@ -0,0 +1,49 @@
+# Copyright (c) 2025 eScience Lab, The University of Manchester
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+@prefix ro: <./> .
+@prefix ro-crate: <https://github.com/crs4/rocrate-validator/profiles/ro-crate/> .
+@prefix five-safes-crate: <https://github.com/eScienceLab/rocrate-validator/profiles/five-safes-crate/> .
+@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix schema: <http://schema.org/> .
+@prefix purl: <http://purl.org/dc/terms/> .
+@prefix sh: <http://www.w3.org/ns/shacl#> .
+@prefix validator: <https://github.com/crs4/rocrate-validator/> .
+@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
+
+
+five-safes-crate::DatasetMustHaveDistributionIfURI
+    a sh:NodeShape ;
+    sh:name "mainEntity" ;
+    sh:targetObjectsOf schema:mainEntity ;
+    sh:description "If mainEntity has an HTTP(S) @id, it SHOULD have a distribution that is an HTTP(S) URL." ;
+
+    sh:sparql [
+        a sh:SPARQLConstraint ;
+        sh:name "distribution" ;
+        sh:description "If mainEntity has an HTTP(S) @id, it SHOULD have a distribution that is an HTTP(S) URL." ;
+        sh:prefixes ro-crate:sparqlPrefixes ;
+        sh:select """
+            SELECT $this
+            WHERE {
+              FILTER (STRSTARTS(STR($this), "http://") || STRSTARTS(STR($this), "https://")) .
+              FILTER NOT EXISTS {
+                $this schema:distribution ?dist .
+                FILTER (STRSTARTS(STR(?dist), "http://") || STRSTARTS(STR(?dist), "https://")) .
+              }
+            }
+        """ ;
+        sh:severity sh:Warning ;
+        sh:message "If mainEntity has an HTTP(S) @id SHOULD have at least one distribution with an HTTP(S) URL." ;
+    ] .
\ No newline at end of file
diff --git a/tests/data/crates/invalid/6_five_safes_crate/funding_project_no_name/ro-crate-metadata.json b/tests/data/crates/invalid/6_five_safes_crate/funding_project_no_name/ro-crate-metadata.json
new file mode 100644
index 00000000..72a411b8
--- /dev/null
+++ b/tests/data/crates/invalid/6_five_safes_crate/funding_project_no_name/ro-crate-metadata.json
@@ -0,0 +1,400 @@
+{
+    "@context": "https://w3id.org/ro/crate/1.1/context",
+    "@graph": [
+        {
+            "@type": "CreativeWork",
+            "@id": "ro-crate-metadata.json",
+            "about": {
+                "@id": "./"
+            },
+            "conformsTo": {
+                "@id": "https://w3id.org/ro/crate/1.1"
+            }
+        },
+        {
+            "@id": "./",
+            "@type": "Dataset",
+            "name": "5-Safe RO-Crate Result",
+            "description": "example 5-Safe RO-Crate result metadata for testing",
+            "datePublished": "2025-09-20T14:45:00+00:00",
+            "conformsTo": {
+                "@id": "https://w3id.org/5s-crate/0.4"
+            },
+            "hasPart": [
+                {
+                    "@id": "https://workflowhub.eu/workflows/289?version=1"
+                },
+                {
+                    "@id": "input1.txt"
+                },
+                {
+                    "@id": "outputs/qa.csv"
+                },
+                {
+                    "@id": "outputs/diagrams/"
+                },
+                {
+                    "@id": "workflow/289/"
+                }
+            ],
+            "mainEntity": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "mentions": [
+                {
+                    "@id": "#query-37252371-c937-43bd-a0a7-3680b48c0538"
+                },
+                {
+                    "@id": "#check-f33fe90c-0c22-4c72-b299-de509028410e"
+                },
+                {
+                    "@id": "#validate-1146f640-819e-4c86-b029-b763a0040896"
+                },
+                {
+                    "@id": "#download-8b51bf57-6b29-44da-b24b-638c8df91639"
+                },
+                {
+                    "@id": "#signoff-3b741265-cfef-49ea-8138-a2fa149bf2f0"
+                },
+                {
+                    "@id": "#disclosure-b16c1f0a-ae7f-4582-9b28-7d9df3313e27"
+                },
+                {
+                    "@id": "#bagit-ce785c0b-c988-4043-8cbd-1489dcebc14f"
+                }
+            ],
+            "sourceOrganization": {
+                "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+            },
+            "publisher": {
+                "@id": "https://tre72.example.com/"
+            },
+            "license": {
+                "@id": "http://spdx.org/licenses/CC-BY-4.0"
+            }
+        },
+        {
+            "@id": "https://w3id.org/5s-crate/0.4",
+            "@type": "Profile",
+            "name": "Five Safes RO-Crate profile"
+        },
+        {
+            "@id": "https://spdx.org/licenses/CC-BY-4.0",
+            "@type": "CreativeWork",
+            "name": "Creative Commons Attribution 4.0 International",
+            "identifier": "CC-BY-4.0"
+        },
+        {
+            "@id": "https://workflowhub.eu/workflows/289?version=1",
+            "@type": "Dataset",
+            "name": "CWL Protein MD Setup tutorial with mutations",
+            "conformsTo": {
+                "@id": "https://w3id.org/workflowhub/workflow-ro-crate/1.0"
+            },
+            "distribution": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            }
+        },
+        {
+            "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1",
+            "@type": "DataDownload",
+            "conformsTo": {
+                "@id": "https://w3id.org/ro/crate"
+            },
+            "encodingFormat": "application/zip"
+        },
+        {
+            "@id": "#query-37252371-c937-43bd-a0a7-3680b48c0538",
+            "@type": "CreateAction",
+            "actionStatus": "http://schema.org/CompleteActionStatus",
+            "agent": {
+                "@id": "https://orcid.org/0000-0001-9842-9718"
+            },
+            "instrument": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "name": "Execute query 12389 on workflow ",
+            "object": [
+                {
+                    "@id": "input1.txt"
+                },
+                {
+                    "@id": "#enableFastMode"
+                }
+            ],
+            "result": [
+                {
+                    "@id": "outputs/qa.csv"
+                },
+                {
+                    "@id": "outputs/diagrams/"
+                },
+                {
+                    "@id": "urn:uuid:07b81e0f-7ac4-5428-9940-878b241e2397"
+                }
+            ]
+        },
+        {
+            "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70",
+            "@type": "Project",
+            "identifier": [
+                {
+                    "@id": "_:localid:tre72:project81"
+                }
+            ],
+            "funding": {
+                "@id": "https://gtr.ukri.org/projects?ref=10038961"
+            },
+            "member": [
+                {
+                    "@id": "https://ror.org/027m9bs27"
+                },
+                {
+                    "@id": "https://ror.org/01ee9ar58"
+                }
+            ]
+        },
+        {
+            "@id": "_:localid:tre72:project81",
+            "@type": "PropertyValue",
+            "name": "tre72",
+            "value": "project81"
+        },        
+        {
+            "@id": "input1.txt",
+            "@type": "File",
+            "name": "input1",
+            "exampleOfWork": {
+                "@id": "#sequence"
+            }
+        },
+        {
+            "@id": "#enableFastMode",
+            "@type": "PropertyValue",
+            "name": "--fast-mode",
+            "value": "True",
+            "exampleOfWork": {
+                "@id": "#fast"
+            }
+        },
+        {
+            "@id": "#sequence",
+            "@type": "FormalParameter",
+            "name": "input-sequence"
+        },
+        {
+            "@id": "#fast",
+            "@type": "FormalParameter",
+            "name": "fast-mode"
+        },
+        {
+            "@id": "outputs/qa.csv",
+            "@type": "File",
+            "encodingFormat": "text/csv",
+            "name": "Tabular listing of quality assessment"
+        },
+        {
+            "@id": "outputs/diagrams/",
+            "@type": "Dataset",
+            "name": "Diagrams of regions of interest"
+        },
+        {
+            "@id": "workflow/289/",
+            "sameAs": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "@type": "Dataset",
+            "name": "CWL Protein MD Setup tutorial with mutations",
+            "conformsTo": {
+                "@id": "https://w3id.org/workflowhub/workflow-ro-crate/1.0"
+            },
+            "distribution": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            }
+        },
+        {
+            "@id": "#check-f33fe90c-0c22-4c72-b299-de509028410e",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#CheckValue"
+            },
+            "name": "BagIt checksum of Crate: OK",
+            "endTime": "2023-04-18T12:11:45+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://www.iana.org/assignments/named-information#sha-512"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#validate-1146f640-819e-4c86-b029-b763a0040896",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#ValidationCheck"
+            },
+            "name": "Validation against Five Safes RO-Crate profile: approved",
+            "startTime": "2023-04-18T12:11:46+01:00",
+            "endTime": "2023-04-18T12:11:49+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://w3id.org/5s-crate/0.4"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#download-8b51bf57-6b29-44da-b24b-638c8df91639",
+            "@type": "DownloadAction",
+            "name": "Downloaded workflow RO-Crate via proxy",
+            "startTime": "2023-04-18T12:11:50+01:00",
+            "endTime": "2023-04-18T12:11:52+01:00",
+            "object": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            },
+            "result": {
+                "@id": "workflow/289/"
+            },
+            "agent": {
+                "@id": "http://proxy.example.com/"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#signoff-3b741265-cfef-49ea-8138-a2fa149bf2f0",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#SignOff"
+            },
+            "name": "Sign-off of execution according to Agreement policy: approved",
+            "endTime": "2023-04-19T17:15:12+01:00",
+            "object": [
+                {
+                    "@id": "./"
+                },
+                {
+                    "@id": "https://workflowhub.eu/workflows/289?version=1"
+                },
+                {
+                    "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+                }
+            ],
+            "instrument": {
+                "@id": "https://tre72.example.com/agreement-policy/81"
+            },
+            "agent": {
+                "@id": "https://orcid.org/0000-0002-1825-0097"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#disclosure-b16c1f0a-ae7f-4582-9b28-7d9df3313e27",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#DisclosureCheck"
+            },
+            "name": "Disclosure check of workflow results: approved",
+            "endTime": "2023-04-25T16:00:00+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "agent": {
+                "@id": "https://orcid.org/0000-0002-1825-0097"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#bagit-ce785c0b-c988-4043-8cbd-1489dcebc14f",
+            "@type": "UpdateAction",
+            "startTime": "2023-04-29T12:12:25+01:00",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#GenerateCheckValue"
+            },
+            "name": "BagIt manifests of Crate updated",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://www.iana.org/assignments/named-information#sha-512"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "urn:uuid:07b81e0f-7ac4-5428-9940-878b241e2397",
+            "@type": "DigitalDocument",
+            "encodingFormat": "text/csv",
+            "name": "Patient measurement 07b81e0f-7ac4-5428-9940-878b241e2397",
+            "hasDigitalDocumentPermission": {
+                "@id": "#permissions-07b81e0f"
+            }
+        },
+        {
+            "@id": "#permissions-07b81e0f",
+            "@type": "DigitalDocumentPermission",
+            "permissionType": "http://schema.org/ReadPermission",
+            "grantee": {
+                "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+            }
+        },
+        {
+            "@id": "https://orcid.org/0000-0001-9842-9718",
+            "@type": "Person",
+            "name": "Stian Soiland-Reyes",
+            "affiliation": {
+                "@id": "https://ror.org/027m9bs27"
+            },
+            "memberOf": [
+                {
+                    "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+                }
+            ]
+        },
+        {
+            "@id": "https://ror.org/027m9bs27",
+            "@type": "Organization",
+            "name": "The University of Manchester"
+        },
+        {
+            "@id": "https://gtr.ukri.org/projects?ref=10038961",
+            "@type": "Grant",
+            "name": "EOSC4Cancer"
+        },
+        {
+            "@id": "https://tre72.example.com/",
+            "@type": "Organization",
+            "name": "TRE 72 trusted research environment at The University of Manchester",
+            "parentOrganization": {
+                "@id": "https://ror.org/027m9bs27"
+            }
+        },
+        {
+            "@id": "https://tre72.example.com/#crate-validator",
+            "@type": "SoftwareApplication",
+            "name": "RO-Crate validator at TRE72",
+            "provider": {
+                "@id": "https://tre72.example.com/"
+            }
+        },
+        {
+            "@id": "https://tre72.example.com/agreement-policy/81",
+            "@type": "CreativeWork",
+            "name": "Agreement policy for TRE72 for project 81"
+        },
+        {
+            "@id": "https://www.iana.org/assignments/named-information#sha-512",
+            "@type": "DefinedTerm",
+            "name": "sha-512 algorithm"
+        }
+    ]
+}
diff --git a/tests/data/crates/invalid/6_five_safes_crate/root_data_entity_no_source_organization/ro-crate-metadata.json b/tests/data/crates/invalid/6_five_safes_crate/root_data_entity_no_source_organization/ro-crate-metadata.json
new file mode 100644
index 00000000..10c51d19
--- /dev/null
+++ b/tests/data/crates/invalid/6_five_safes_crate/root_data_entity_no_source_organization/ro-crate-metadata.json
@@ -0,0 +1,398 @@
+{
+    "@context": "https://w3id.org/ro/crate/1.1/context",
+    "@graph": [
+        {
+            "@type": "CreativeWork",
+            "@id": "ro-crate-metadata.json",
+            "about": {
+                "@id": "./"
+            },
+            "conformsTo": {
+                "@id": "https://w3id.org/ro/crate/1.1"
+            }
+        },
+        {
+            "@id": "./",
+            "@type": "Dataset",
+            "name": "5-Safe RO-Crate Result",
+            "description": "example 5-Safe RO-Crate result metadata for testing",
+            "datePublished": "2025-09-20T14:45:00+00:00",
+            "conformsTo": {
+                "@id": "https://w3id.org/5s-crate/0.4"
+            },
+            "hasPart": [
+                {
+                    "@id": "https://workflowhub.eu/workflows/289?version=1"
+                },
+                {
+                    "@id": "input1.txt"
+                },
+                {
+                    "@id": "outputs/qa.csv"
+                },
+                {
+                    "@id": "outputs/diagrams/"
+                },
+                {
+                    "@id": "workflow/289/"
+                }
+            ],
+            "mainEntity": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "mentions": [
+                {
+                    "@id": "#query-37252371-c937-43bd-a0a7-3680b48c0538"
+                },
+                {
+                    "@id": "#check-f33fe90c-0c22-4c72-b299-de509028410e"
+                },
+                {
+                    "@id": "#validate-1146f640-819e-4c86-b029-b763a0040896"
+                },
+                {
+                    "@id": "#download-8b51bf57-6b29-44da-b24b-638c8df91639"
+                },
+                {
+                    "@id": "#signoff-3b741265-cfef-49ea-8138-a2fa149bf2f0"
+                },
+                {
+                    "@id": "#disclosure-b16c1f0a-ae7f-4582-9b28-7d9df3313e27"
+                },
+                {
+                    "@id": "#bagit-ce785c0b-c988-4043-8cbd-1489dcebc14f"
+                }
+            ],
+            "publisher": {
+                "@id": "https://tre72.example.com/"
+            },
+            "license": {
+                "@id": "http://spdx.org/licenses/CC-BY-4.0"
+            }
+        },
+        {
+            "@id": "https://w3id.org/5s-crate/0.4",
+            "@type": "Profile",
+            "name": "Five Safes RO-Crate profile"
+        },
+        {
+            "@id": "https://spdx.org/licenses/CC-BY-4.0",
+            "@type": "CreativeWork",
+            "name": "Creative Commons Attribution 4.0 International",
+            "identifier": "CC-BY-4.0"
+        },
+        {
+            "@id": "https://workflowhub.eu/workflows/289?version=1",
+            "@type": "Dataset",
+            "name": "CWL Protein MD Setup tutorial with mutations",
+            "conformsTo": {
+                "@id": "https://w3id.org/workflowhub/workflow-ro-crate/1.0"
+            },
+            "distribution": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            }
+        },
+        {
+            "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1",
+            "@type": "DataDownload",
+            "conformsTo": {
+                "@id": "https://w3id.org/ro/crate"
+            },
+            "encodingFormat": "application/zip"
+        },
+        {
+            "@id": "#query-37252371-c937-43bd-a0a7-3680b48c0538",
+            "@type": "CreateAction",
+            "actionStatus": "http://schema.org/CompleteActionStatus",
+            "agent": {
+                "@id": "https://orcid.org/0000-0001-9842-9718"
+            },
+            "instrument": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "name": "Execute query 12389 on workflow ",
+            "object": [
+                {
+                    "@id": "input1.txt"
+                },
+                {
+                    "@id": "#enableFastMode"
+                }
+            ],
+            "result": [
+                {
+                    "@id": "outputs/qa.csv"
+                },
+                {
+                    "@id": "outputs/diagrams/"
+                },
+                {
+                    "@id": "urn:uuid:07b81e0f-7ac4-5428-9940-878b241e2397"
+                }
+            ]
+        },
+        {
+            "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70",
+            "@type": "Project",
+            "name": "Investigation of cancer (TRE72 project 81)",
+            "identifier": [
+                {
+                    "@id": "_:localid:tre72:project81"
+                }
+            ],
+            "funding": {
+                "@id": "https://gtr.ukri.org/projects?ref=10038961"
+            },
+            "member": [
+                {
+                    "@id": "https://ror.org/027m9bs27"
+                },
+                {
+                    "@id": "https://ror.org/01ee9ar58"
+                }
+            ]
+        },
+        {
+            "@id": "_:localid:tre72:project81",
+            "@type": "PropertyValue",
+            "name": "tre72",
+            "value": "project81"
+        },        
+        {
+            "@id": "input1.txt",
+            "@type": "File",
+            "name": "input1",
+            "exampleOfWork": {
+                "@id": "#sequence"
+            }
+        },
+        {
+            "@id": "#enableFastMode",
+            "@type": "PropertyValue",
+            "name": "--fast-mode",
+            "value": "True",
+            "exampleOfWork": {
+                "@id": "#fast"
+            }
+        },
+        {
+            "@id": "#sequence",
+            "@type": "FormalParameter",
+            "name": "input-sequence"
+        },
+        {
+            "@id": "#fast",
+            "@type": "FormalParameter",
+            "name": "fast-mode"
+        },
+        {
+            "@id": "outputs/qa.csv",
+            "@type": "File",
+            "encodingFormat": "text/csv",
+            "name": "Tabular listing of quality assessment"
+        },
+        {
+            "@id": "outputs/diagrams/",
+            "@type": "Dataset",
+            "name": "Diagrams of regions of interest"
+        },
+        {
+            "@id": "workflow/289/",
+            "sameAs": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "@type": "Dataset",
+            "name": "CWL Protein MD Setup tutorial with mutations",
+            "conformsTo": {
+                "@id": "https://w3id.org/workflowhub/workflow-ro-crate/1.0"
+            },
+            "distribution": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            }
+        },
+        {
+            "@id": "#check-f33fe90c-0c22-4c72-b299-de509028410e",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#CheckValue"
+            },
+            "name": "BagIt checksum of Crate: OK",
+            "endTime": "2023-04-18T12:11:45+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://www.iana.org/assignments/named-information#sha-512"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#validate-1146f640-819e-4c86-b029-b763a0040896",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#ValidationCheck"
+            },
+            "name": "Validation against Five Safes RO-Crate profile: approved",
+            "startTime": "2023-04-18T12:11:46+01:00",
+            "endTime": "2023-04-18T12:11:49+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://w3id.org/5s-crate/0.4"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#download-8b51bf57-6b29-44da-b24b-638c8df91639",
+            "@type": "DownloadAction",
+            "name": "Downloaded workflow RO-Crate via proxy",
+            "startTime": "2023-04-18T12:11:50+01:00",
+            "endTime": "2023-04-18T12:11:52+01:00",
+            "object": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            },
+            "result": {
+                "@id": "workflow/289/"
+            },
+            "agent": {
+                "@id": "http://proxy.example.com/"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#signoff-3b741265-cfef-49ea-8138-a2fa149bf2f0",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#SignOff"
+            },
+            "name": "Sign-off of execution according to Agreement policy: approved",
+            "endTime": "2023-04-19T17:15:12+01:00",
+            "object": [
+                {
+                    "@id": "./"
+                },
+                {
+                    "@id": "https://workflowhub.eu/workflows/289?version=1"
+                },
+                {
+                    "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+                }
+            ],
+            "instrument": {
+                "@id": "https://tre72.example.com/agreement-policy/81"
+            },
+            "agent": {
+                "@id": "https://orcid.org/0000-0002-1825-0097"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#disclosure-b16c1f0a-ae7f-4582-9b28-7d9df3313e27",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#DisclosureCheck"
+            },
+            "name": "Disclosure check of workflow results: approved",
+            "endTime": "2023-04-25T16:00:00+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "agent": {
+                "@id": "https://orcid.org/0000-0002-1825-0097"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#bagit-ce785c0b-c988-4043-8cbd-1489dcebc14f",
+            "@type": "UpdateAction",
+            "startTime": "2023-04-29T12:12:25+01:00",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#GenerateCheckValue"
+            },
+            "name": "BagIt manifests of Crate updated",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://www.iana.org/assignments/named-information#sha-512"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "urn:uuid:07b81e0f-7ac4-5428-9940-878b241e2397",
+            "@type": "DigitalDocument",
+            "encodingFormat": "text/csv",
+            "name": "Patient measurement 07b81e0f-7ac4-5428-9940-878b241e2397",
+            "hasDigitalDocumentPermission": {
+                "@id": "#permissions-07b81e0f"
+            }
+        },
+        {
+            "@id": "#permissions-07b81e0f",
+            "@type": "DigitalDocumentPermission",
+            "permissionType": "http://schema.org/ReadPermission",
+            "grantee": {
+                "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+            }
+        },
+        {
+            "@id": "https://orcid.org/0000-0001-9842-9718",
+            "@type": "Person",
+            "name": "Stian Soiland-Reyes",
+            "affiliation": {
+                "@id": "https://ror.org/027m9bs27"
+            },
+            "memberOf": [
+                {
+                    "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+                }
+            ]
+        },
+        {
+            "@id": "https://ror.org/027m9bs27",
+            "@type": "Organization",
+            "name": "The University of Manchester"
+        },
+        {
+            "@id": "https://gtr.ukri.org/projects?ref=10038961",
+            "@type": "Grant",
+            "name": "EOSC4Cancer"
+        },
+        {
+            "@id": "https://tre72.example.com/",
+            "@type": "Organization",
+            "name": "TRE 72 trusted research environment at The University of Manchester",
+            "parentOrganization": {
+                "@id": "https://ror.org/027m9bs27"
+            }
+        },
+        {
+            "@id": "https://tre72.example.com/#crate-validator",
+            "@type": "SoftwareApplication",
+            "name": "RO-Crate validator at TRE72",
+            "provider": {
+                "@id": "https://tre72.example.com/"
+            }
+        },
+        {
+            "@id": "https://tre72.example.com/agreement-policy/81",
+            "@type": "CreativeWork",
+            "name": "Agreement policy for TRE72 for project 81"
+        },
+        {
+            "@id": "https://www.iana.org/assignments/named-information#sha-512",
+            "@type": "DefinedTerm",
+            "name": "sha-512 algorithm"
+        }
+    ]
+}
diff --git a/tests/data/crates/invalid/6_five_safes_crate/root_data_entity_source_organization_not_entity/ro-crate-metadata.json b/tests/data/crates/invalid/6_five_safes_crate/root_data_entity_source_organization_not_entity/ro-crate-metadata.json
new file mode 100644
index 00000000..e181d903
--- /dev/null
+++ b/tests/data/crates/invalid/6_five_safes_crate/root_data_entity_source_organization_not_entity/ro-crate-metadata.json
@@ -0,0 +1,399 @@
+{
+    "@context": "https://w3id.org/ro/crate/1.1/context",
+    "@graph": [
+        {
+            "@type": "CreativeWork",
+            "@id": "ro-crate-metadata.json",
+            "about": {
+                "@id": "./"
+            },
+            "conformsTo": {
+                "@id": "https://w3id.org/ro/crate/1.1"
+            }
+        },
+        {
+            "@id": "./",
+            "@type": "Dataset",
+            "name": "5-Safe RO-Crate Result",
+            "description": "example 5-Safe RO-Crate result metadata for testing",
+            "datePublished": "2025-09-20T14:45:00+00:00",
+            "conformsTo": {
+                "@id": "https://w3id.org/5s-crate/0.4"
+            },
+            "hasPart": [
+                {
+                    "@id": "https://workflowhub.eu/workflows/289?version=1"
+                },
+                {
+                    "@id": "input1.txt"
+                },
+                {
+                    "@id": "outputs/qa.csv"
+                },
+                {
+                    "@id": "outputs/diagrams/"
+                },
+                {
+                    "@id": "workflow/289/"
+                }
+            ],
+            "mainEntity": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "mentions": [
+                {
+                    "@id": "#query-37252371-c937-43bd-a0a7-3680b48c0538"
+                },
+                {
+                    "@id": "#check-f33fe90c-0c22-4c72-b299-de509028410e"
+                },
+                {
+                    "@id": "#validate-1146f640-819e-4c86-b029-b763a0040896"
+                },
+                {
+                    "@id": "#download-8b51bf57-6b29-44da-b24b-638c8df91639"
+                },
+                {
+                    "@id": "#signoff-3b741265-cfef-49ea-8138-a2fa149bf2f0"
+                },
+                {
+                    "@id": "#disclosure-b16c1f0a-ae7f-4582-9b28-7d9df3313e27"
+                },
+                {
+                    "@id": "#bagit-ce785c0b-c988-4043-8cbd-1489dcebc14f"
+                }
+            ],
+            "sourceOrganization": "Investigation of cancer (TRE72 project 81)",
+            "publisher": {
+                "@id": "https://tre72.example.com/"
+            },
+            "license": {
+                "@id": "http://spdx.org/licenses/CC-BY-4.0"
+            }
+        },
+        {
+            "@id": "https://w3id.org/5s-crate/0.4",
+            "@type": "Profile",
+            "name": "Five Safes RO-Crate profile"
+        },
+        {
+            "@id": "https://spdx.org/licenses/CC-BY-4.0",
+            "@type": "CreativeWork",
+            "name": "Creative Commons Attribution 4.0 International",
+            "identifier": "CC-BY-4.0"
+        },
+        {
+            "@id": "https://workflowhub.eu/workflows/289?version=1",
+            "@type": "Dataset",
+            "name": "CWL Protein MD Setup tutorial with mutations",
+            "conformsTo": {
+                "@id": "https://w3id.org/workflowhub/workflow-ro-crate/1.0"
+            },
+            "distribution": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            }
+        },
+        {
+            "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1",
+            "@type": "DataDownload",
+            "conformsTo": {
+                "@id": "https://w3id.org/ro/crate"
+            },
+            "encodingFormat": "application/zip"
+        },
+        {
+            "@id": "#query-37252371-c937-43bd-a0a7-3680b48c0538",
+            "@type": "CreateAction",
+            "actionStatus": "http://schema.org/CompleteActionStatus",
+            "agent": {
+                "@id": "https://orcid.org/0000-0001-9842-9718"
+            },
+            "instrument": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "name": "Execute query 12389 on workflow ",
+            "object": [
+                {
+                    "@id": "input1.txt"
+                },
+                {
+                    "@id": "#enableFastMode"
+                }
+            ],
+            "result": [
+                {
+                    "@id": "outputs/qa.csv"
+                },
+                {
+                    "@id": "outputs/diagrams/"
+                },
+                {
+                    "@id": "urn:uuid:07b81e0f-7ac4-5428-9940-878b241e2397"
+                }
+            ]
+        },
+        {
+            "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70",
+            "@type": "Project",
+            "name": "Investigation of cancer (TRE72 project 81)",
+            "identifier": [
+                {
+                    "@id": "_:localid:tre72:project81"
+                }
+            ],
+            "funding": {
+                "@id": "https://gtr.ukri.org/projects?ref=10038961"
+            },
+            "member": [
+                {
+                    "@id": "https://ror.org/027m9bs27"
+                },
+                {
+                    "@id": "https://ror.org/01ee9ar58"
+                }
+            ]
+        },
+        {
+            "@id": "_:localid:tre72:project81",
+            "@type": "PropertyValue",
+            "name": "tre72",
+            "value": "project81"
+        },        
+        {
+            "@id": "input1.txt",
+            "@type": "File",
+            "name": "input1",
+            "exampleOfWork": {
+                "@id": "#sequence"
+            }
+        },
+        {
+            "@id": "#enableFastMode",
+            "@type": "PropertyValue",
+            "name": "--fast-mode",
+            "value": "True",
+            "exampleOfWork": {
+                "@id": "#fast"
+            }
+        },
+        {
+            "@id": "#sequence",
+            "@type": "FormalParameter",
+            "name": "input-sequence"
+        },
+        {
+            "@id": "#fast",
+            "@type": "FormalParameter",
+            "name": "fast-mode"
+        },
+        {
+            "@id": "outputs/qa.csv",
+            "@type": "File",
+            "encodingFormat": "text/csv",
+            "name": "Tabular listing of quality assessment"
+        },
+        {
+            "@id": "outputs/diagrams/",
+            "@type": "Dataset",
+            "name": "Diagrams of regions of interest"
+        },
+        {
+            "@id": "workflow/289/",
+            "sameAs": {
+                "@id": "https://workflowhub.eu/workflows/289?version=1"
+            },
+            "@type": "Dataset",
+            "name": "CWL Protein MD Setup tutorial with mutations",
+            "conformsTo": {
+                "@id": "https://w3id.org/workflowhub/workflow-ro-crate/1.0"
+            },
+            "distribution": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            }
+        },
+        {
+            "@id": "#check-f33fe90c-0c22-4c72-b299-de509028410e",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#CheckValue"
+            },
+            "name": "BagIt checksum of Crate: OK",
+            "endTime": "2023-04-18T12:11:45+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://www.iana.org/assignments/named-information#sha-512"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#validate-1146f640-819e-4c86-b029-b763a0040896",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#ValidationCheck"
+            },
+            "name": "Validation against Five Safes RO-Crate profile: approved",
+            "startTime": "2023-04-18T12:11:46+01:00",
+            "endTime": "2023-04-18T12:11:49+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://w3id.org/5s-crate/0.4"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#download-8b51bf57-6b29-44da-b24b-638c8df91639",
+            "@type": "DownloadAction",
+            "name": "Downloaded workflow RO-Crate via proxy",
+            "startTime": "2023-04-18T12:11:50+01:00",
+            "endTime": "2023-04-18T12:11:52+01:00",
+            "object": {
+                "@id": "https://workflowhub.eu/workflows/289/ro_crate?version=1"
+            },
+            "result": {
+                "@id": "workflow/289/"
+            },
+            "agent": {
+                "@id": "http://proxy.example.com/"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#signoff-3b741265-cfef-49ea-8138-a2fa149bf2f0",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#SignOff"
+            },
+            "name": "Sign-off of execution according to Agreement policy: approved",
+            "endTime": "2023-04-19T17:15:12+01:00",
+            "object": [
+                {
+                    "@id": "./"
+                },
+                {
+                    "@id": "https://workflowhub.eu/workflows/289?version=1"
+                },
+                {
+                    "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+                }
+            ],
+            "instrument": {
+                "@id": "https://tre72.example.com/agreement-policy/81"
+            },
+            "agent": {
+                "@id": "https://orcid.org/0000-0002-1825-0097"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#disclosure-b16c1f0a-ae7f-4582-9b28-7d9df3313e27",
+            "@type": "AssessAction",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#DisclosureCheck"
+            },
+            "name": "Disclosure check of workflow results: approved",
+            "endTime": "2023-04-25T16:00:00+01:00",
+            "object": {
+                "@id": "./"
+            },
+            "agent": {
+                "@id": "https://orcid.org/0000-0002-1825-0097"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "#bagit-ce785c0b-c988-4043-8cbd-1489dcebc14f",
+            "@type": "UpdateAction",
+            "startTime": "2023-04-29T12:12:25+01:00",
+            "additionalType": {
+                "@id": "https://w3id.org/shp#GenerateCheckValue"
+            },
+            "name": "BagIt manifests of Crate updated",
+            "object": {
+                "@id": "./"
+            },
+            "instrument": {
+                "@id": "https://www.iana.org/assignments/named-information#sha-512"
+            },
+            "agent": {
+                "@id": "#validator-a4a66c63-2fe0-4c57-830d-268a40718313"
+            },
+            "actionStatus": "http://schema.org/CompletedActionStatus"
+        },
+        {
+            "@id": "urn:uuid:07b81e0f-7ac4-5428-9940-878b241e2397",
+            "@type": "DigitalDocument",
+            "encodingFormat": "text/csv",
+            "name": "Patient measurement 07b81e0f-7ac4-5428-9940-878b241e2397",
+            "hasDigitalDocumentPermission": {
+                "@id": "#permissions-07b81e0f"
+            }
+        },
+        {
+            "@id": "#permissions-07b81e0f",
+            "@type": "DigitalDocumentPermission",
+            "permissionType": "http://schema.org/ReadPermission",
+            "grantee": {
+                "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+            }
+        },
+        {
+            "@id": "https://orcid.org/0000-0001-9842-9718",
+            "@type": "Person",
+            "name": "Stian Soiland-Reyes",
+            "affiliation": {
+                "@id": "https://ror.org/027m9bs27"
+            },
+            "memberOf": [
+                {
+                    "@id": "#project-be6ffb55-4f5a-4c14-b60e-47e0951090c70"
+                }
+            ]
+        },
+        {
+            "@id": "https://ror.org/027m9bs27",
+            "@type": "Organization",
+            "name": "The University of Manchester"
+        },
+        {
+            "@id": "https://gtr.ukri.org/projects?ref=10038961",
+            "@type": "Grant",
+            "name": "EOSC4Cancer"
+        },
+        {
+            "@id": "https://tre72.example.com/",
+            "@type": "Organization",
+            "name": "TRE 72 trusted research environment at The University of Manchester",
+            "parentOrganization": {
+                "@id": "https://ror.org/027m9bs27"
+            }
+        },
+        {
+            "@id": "https://tre72.example.com/#crate-validator",
+            "@type": "SoftwareApplication",
+            "name": "RO-Crate validator at TRE72",
+            "provider": {
+                "@id": "https://tre72.example.com/"
+            }
+        },
+        {
+            "@id": "https://tre72.example.com/agreement-policy/81",
+            "@type": "CreativeWork",
+            "name": "Agreement policy for TRE72 for project 81"
+        },
+        {
+            "@id": "https://www.iana.org/assignments/named-information#sha-512",
+            "@type": "DefinedTerm",
+            "name": "sha-512 algorithm"
+        }
+    ]
+}
diff --git a/tests/integration/profiles/five-safes-crate/test_5src_6_workflow_reference.py b/tests/integration/profiles/five-safes-crate/test_5src_6_workflow_reference.py
new file mode 100644
index 00000000..d61803c7
--- /dev/null
+++ b/tests/integration/profiles/five-safes-crate/test_5src_6_workflow_reference.py
@@ -0,0 +1,161 @@
+# Copyright (c) 2024-2025 CRS4
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+
+from rocrate_validator.models import Severity
+from tests.ro_crates import ValidROC
+from tests.shared import do_entity_test, SPARQL_PREFIXES
+
+# set up logging
+logger = logging.getLogger(__name__)
+
+
+# ----- MUST fails tests
+
+
+def test_5src_root_data_entity_no_main_entity():
+    """
+    Remove the RootDataEntity's mainEntity so minCount=1 is violated.
+    """
+    sparql = (
+        SPARQL_PREFIXES
+        + """
+        DELETE {
+            <./> schema:mainEntity ?m .
+        }
+        WHERE {
+            <./> schema:mainEntity ?m .
+        }
+        """
+    )
+
+    do_entity_test(
+        rocrate_path=ValidROC().five_safes_crate_request,
+        requirement_severity=Severity.REQUIRED,
+        expected_validation_result=False,
+        expected_triggered_requirements=["RootDataEntity"],
+        expected_triggered_issues=[
+            "The RootDataEntity MUST have exactly one schema:mainEntity property that is an IRI."
+        ],
+        profile_identifier="five-safes-crate",
+        rocrate_entity_mod_sparql=sparql,
+    )
+
+
+def test_5src_root_data_entity_main_entity_not_dataset_iri():
+    """
+    Test a Five Safes Crate where the RootDataEntity's mainEntity is an IRI but not typed as schema:Dataset.
+    (We point mainEntity to a new crate-local entity typed as something else.)
+    """
+    sparql = (
+        SPARQL_PREFIXES
+        + """
+        DELETE {
+            <./> schema:mainEntity ?m .
+        }
+        INSERT {
+            # add an IRI that is NOT typed as schema:Dataset (e.g. a schema:SoftwareSourceCode)
+            <./> schema:mainEntity <./not-a-dataset> .
+            <./not-a-dataset> a schema:SoftwareSourceCode .
+        }
+        WHERE {
+            <./> schema:mainEntity ?m .
+        }
+        """
+    )
+
+    do_entity_test(
+        rocrate_path=ValidROC().five_safes_crate_request,
+        requirement_severity=Severity.REQUIRED,
+        expected_validation_result=False,
+        expected_triggered_requirements=["RootDataEntity"],
+        expected_triggered_issues=[
+            "The mainEntity pointed to by the RootDataEntity MUST be of type schema:Dataset"
+        ],
+        profile_identifier="five-safes-crate",
+        rocrate_entity_mod_sparql=sparql,
+    )
+
+
+def test_5src_main_entity_conformsTo_invalid():
+    """
+    Test a Five Safes Crate where the mainEntity's purl:conformsTo IRI does NOT start with
+    "https://w3id.org/workflowhub/workflow-ro-crate" (violates the SHACL SPARQL constraint).
+    """
+    sparql = (
+        SPARQL_PREFIXES
+        + """
+        PREFIX purl: <http://purl.org/dc/terms/>
+        DELETE {
+            ?dataset purl:conformsTo ?iri .
+        }
+        INSERT {
+            ?dataset purl:conformsTo <http://example.org/not-workflow-ro-crate> .
+        }
+        WHERE {
+            <./> schema:mainEntity ?dataset .
+            ?dataset purl:conformsTo ?iri .
+            FILTER(STRSTARTS(STR(?iri), "https://w3id.org/workflowhub/workflow-ro-crate"))
+        }
+        """
+    )
+
+    do_entity_test(
+        rocrate_path=ValidROC().five_safes_crate_request,
+        requirement_severity=Severity.REQUIRED,
+        expected_validation_result=False,
+        expected_triggered_requirements=["mainEntity"],
+        expected_triggered_issues=[
+            "conformsTo IRI must start with https://w3id.org/workflowhub/workflow-ro-crate"
+        ],
+        profile_identifier="five-safes-crate",
+        rocrate_entity_mod_sparql=sparql,
+    )
+
+
+# ----- SHOULD fails tests
+
+
+def test_5src_main_entity_missing_distribution_warning():
+    """
+    Test a Five Safes Crate where a mainEntity has an HTTP(S) IRI but no distribution with an HTTP(S) URL.
+    This should trigger the SHACL warning about missing or non-HTTP(S) distributions.
+    """
+    sparql = (
+        SPARQL_PREFIXES
+        + """
+        DELETE {
+            ?dataset schema:distribution ?dist .
+        }
+        WHERE {
+            <./> schema:mainEntity ?dataset .
+            ?dataset schema:distribution ?dist .
+            FILTER (STRSTARTS(STR(?dataset), "http://") || STRSTARTS(STR(?dataset), "https://")) .
+            FILTER (STRSTARTS(STR(?dist), "http://") || STRSTARTS(STR(?dist), "https://")) .
+        }
+        """
+    )
+
+    do_entity_test(
+        rocrate_path=ValidROC().five_safes_crate_request,
+        requirement_severity=Severity.RECOMMENDED,
+        expected_validation_result=False,
+        expected_triggered_requirements=["mainEntity"],
+        expected_triggered_issues=[
+            "If mainEntity has an HTTP(S) @id SHOULD have at least one distribution with an HTTP(S) URL."
+        ],
+        profile_identifier="five-safes-crate",
+        rocrate_entity_mod_sparql=sparql,
+    )