diff --git a/Skills/JavaScript.md b/Skills/JavaScript.md
index 0ff8fc89..fa095170 100644
--- a/Skills/JavaScript.md
+++ b/Skills/JavaScript.md
@@ -1,25 +1,25 @@
 ## JavaScript
 
 - Language
-  - `Object`
-  - `Function`
-  - `Boolean`
-  - `Number`
-  - `BigInt`
-  - `String`
-  - `Symbol`
-  - `Infinity`
-  - `NaN`
-  - `undefined`
-  - `null`
-  - `this`
+  - `Object` e
+  - `Function` e
+  - `Boolean` e
+  - `Number` e
+  - `BigInt` e
+  - `String` e
+  - `Symbol` e
+  - `Infinity` k
+  - `NaN` k
+  - `undefined` k
+  - `null` k
+  - `this` h
   - `instanceof`
   - `...spread`
   - `...rest`
-  - `typeof`
+  - `typeof`u
   - Destructuring
   - Generators
-  - Iterators
+  - Iterators h
   - Async generator
   - Async iterator
   - Chaining
@@ -28,7 +28,7 @@
   - Async IIFE
   - `global`
   - `globalThis`
-  - `window`
+  - `window` k
   - Getters and setters
   - `__proto__`
   - `prototype`
@@ -59,30 +59,30 @@
   - Private class fields
   - Private class methods
 - Statements
-  - `if`
-  - `while`
-  - `do..while`
-  - `for`
-  - `for..in`
-  - `for..of`
-  - `for await`
-  - `throw`
-  - `break`
-  - `continue`
+  - `if` u
+  - `while` u
+  - `do..while` u
+  - `for` u
+  - `for..in` u
+  - `for..of` u
+  - `for await` u
+  - `throw` u
+  - `break` u
+  - `continue` u
   - `import`
   - `export`
   - `label`
   - `try..catch`
-  - `switch`
-  - `class`
+  - `switch` k
+  - `class` k
   - `extends`
   - `with`
   - `new`
 - Functions
-  - Arrow function
-  - Async function
-  - Function declaration
-  - Function expression
+  - Arrow function u
+  - Async function u
+  - Function declaration u
+  - Function expression u
   - Default parameters
   - Functional object
   - `Function.prototype.call`
@@ -90,7 +90,7 @@
   - `Function.prototype.apply`
   - `return`
 - Data structures
-  - `Array`
+  - `Array` k
   - `Map`
   - `Set`
   - `WeakMap`
@@ -102,21 +102,21 @@
   - `Proxy`
   - `RegExp`
   - `Date`
-  - `Math`
+  - `Math` u
   - `Reflect`
-  - `Error`
+  - `Error` ~
   - `Atomics`
-  - `JSON`
+  - `JSON` ~
   - `WeakRef`
   - `FinalizationRegistry`
   - `Intl`
   - `Promise`
-  - `console`
+  - `console` u
   - Timers
 - Infrastructure
   - V8
   - Node.js
-  - npm
+  - npm ~
   - prettier
   - MDN
   - TC39
diff --git a/Skills/Programming.md b/Skills/Programming.md
index e976b503..47503e70 100644
--- a/Skills/Programming.md
+++ b/Skills/Programming.md
@@ -1,67 +1,67 @@
 ## Programming fundamental concepts
 
 - Concepts
-  - Model
-  - Modeling
+  - Model ~
+  - Modeling ~
   - Subject domain
-  - Algorithm
+  - Algorithm k
   - Syntax
   - Semantics
   - Abstraction
-  - Paradigm
-  - Programm
-  - Programming paradigm
-  - Programming language
-  - Contract
+  - Paradigm ~
+  - Programm e
+  - Programming paradigm ~
+  - Programming language ~
+  - Contract ~
   - Module
-  - Library
-  - Package
+  - Library ~
+  - Package ~
   - Component
-  - Framework
-  - Platform
-  - Source code
+  - Framework~
+  - Platform ~
+  - Source code k
   - Object code
-  - Machine code
-  - Microcode
-  - Software engineering
+  - Machine code k
+  - Microcode ~
+  - Software engineering k
   - Decomposition
   - Control flow
   - Data flow
   - Code reuse
   - Defensive programming
-  - Don't repeat yourself (DRY)
-  - KISS principle
+  - Don't repeat yourself (DRY) e
+  - KISS principle e
 - Syntax and concepts
-  - Value
-  - Identifier
-  - Variable
-  - Constant
-  - Scalar
-  - Literal
-  - Expression
+  - Value u
+  - Identifier u
+  - Variable u
+  - Constant u
+  - Scalar u
+  - Literal u
+  - Expression u
   - Heap
-  - Function
+  - Function u
   - Procedure
   - Method
-  - Class
+  - Class u
   - Prototype
-  - Event
+  - Event u
   - Type
   - Flag
   - Lexical scope
   - Code block
   - Conditions
-  - Loops
-  - Assignment
+  - Loops ~
+  - Assignment k
   - Regular expression
   - Interface
   - Namespaces
   - Call stack
   - Naming conventions
   - Coding conventions
-  - Camel case
-  - Snake case
-  - Kebab case
+  - Camel case u
+  - Snake case u
+  - Kebab case u
   - Trailing commas
   - Return early
   - Fail-fast
@@ -81,9 +81,9 @@
   - Covariance
   - Contravariance
 - Functions
-  - Signature
-  - Argument
-  - Parameter
+  - Signature u
+  - Argument u
+  - Parameter u
   - Pure function
   - Lambda expression
   - Side effects
@@ -105,12 +105,12 @@
   - Generator
   - Coroutine
 - Data structures
-  - Array
+  - Array u
   - Structure
   - Record
   - Enum
   - Instance
-  - Object
+  - Object u
   - Collection
   - Set
   - Hash table
@@ -128,7 +128,7 @@
   - Immutable state
   - Serialization
   - String parsing
-  - JSON
+  - JSON ~
   - JSON5
   - YAML
 - Networking
@@ -164,16 +164,16 @@
   - Code review
   - Exception
   - Unittesting
-  - git
-  - Github
+  - git u
+  - Github u
   - Docker
   - Kubernetes
   - GCC
   - LLVM
 - Antipatterns
-  - Magic numbers
-  - Hard code
-  - Soft code
+  - Magic numbers ~
+  - Hard code ~
+  - Soft code ~
   - Cryptic code
   - Improbability factor
   - Accidental complexity
@@ -181,9 +181,9 @@
   - Spaghetti
   - Silver bullet
   - Not invented here
-  - Dead code
-  - Unreachable code
-  - Duplicate code
+  - Dead code ~
+  - Unreachable code ~
+  - Duplicate code k
   - Premature optimization
   - Micro-optimization
   - Nested loops
@@ -209,20 +209,20 @@
   - Mono
 - Operating systems
   - Interrupts
-  - Drivers
-  - Kernel
+  - Drivers u
+  - Kernel ~
   - Ring
-  - Virtual memory
-  - File system
-  - Linux
+  - Virtual memory u
+  - File system u
+  - Linux u
   - Unix
   - BSD
-  - MacOS
-  - Windows
+  - MacOS k
+  - Windows u
   - Real-time OS
   - Embedded OS
 - Standards
-  - ASCII
+  - ASCII ~
   - Escape sequence
   - RFC
   - IETF