Sentence:  Here then is a letter from a young man whose name I must not reveal, but whom I will designate as D. F., and whose address I must not <WSD>divulge</WSD>, but will simply indicate as Q. Street, West. 
Meaning of the word marked with <WSD> tags:  To make public or known; to communicate to the public; to tell (information, especially a secret) so that it may become generally known