A little context would be nice, but that's probably the word you're looking for :-)

i thouhgt that feedback is more or less an opinion on something.

what I mean is the "returning of documents" but I don't want to use the word document and "return run of information" sounds not so good or is itok

many thanks

again - what is the context? If it is a heading in a timeline, then "return/submit the requested information" is okay. Or if you're talking about questionnaires, "return questionnaires" would be the word. Why don't you want to use "documents"?