Are you asking within the context of linked fields?  If so, yeap, they are

Thanks for the response.  My question was not well formed.  What I want to understand is (i) does airtable enforce unique primary fields (i.e. will not allow two records to have the identical primary field), (ii) are two records with identical primary field spelling but different capitalization considered distinct primary fields; hence case sensitive (independent of linked fields).

> (i) does airtable enforce unique primary fields (i.e. will not allow two records to have the identical primary field)
Nope, it doesn't enforce unique primary fields and will allow two records to have the identical primary field

> (ii) are two records with identical primary field spelling but different capitalization considered distinct primary fields; hence case sensitive (independent of linked fields).
I think so yeah.  Each record has a unique record ID accessible via a formula field with the formula `RECORD_ID()`, and so two records with identical primary field spelling but different capitalization would still be treated differently

Apologies if I've misunderstood your questions!