This is the 502nd most frequent Ukrainian word.
документів
"Документів" means "of documents" (genitive plural of "документ").
'Документів' is in the genitive plural form, used here to describe the contents of the folder.
Я взяв папку, повну різних документів.
I took a folder full of various documents.
'Документів' is in the genitive plural form, used here to specify what kind of verification is needed.
Для подорожі вам потрібна перевірка документів.
For the trip, you need document verification.
'Документів' is in the genitive plural form, indicating possession, specifying whose list to review.