Go back and look at the spelling; the word was DESCRIPTOR.
DESCRIPTOR: something (as a word or characteristic feature) that serves to describe or identify; a word or phrase (as an index term) used to identify an item (as a subject or document) in an information retrieval system.
‘...in an information retrieval system.’
Ah, I see - you’re a computer person. No wonder I don’t understand a word...
Sorry, I was already into middle age when the darned things came out.