Collocations for anonymous - adj.

be
become
remain, stay

completely, entirely (esp. BrE), totally
largely, relatively
the largely anonymous perpetrators of terrorist acts

prefer to remain anonymous, wish to remain anonymous
My client wishes to remain anonymous.

Anonymous is used with these nouns:
author, benefactor, call, donation, donor, editorial, letter, message, poem, quote, report, sex, source, tip, tip-off, writer