What article on segment.com/docs is affected?

https://segment.com/docs/unify/profile-api/

What part(s) of the article would you like to see updated?

With the profile API it is critical to query the external_ids only with lowercase. Here is an example
email:[email protected]

If we use any other casing, like CamelCase or uppercase, that won't fetch the results.

Additional information

No response