poste restante vs annotation

poste restante and annotation both are nouns.

Word	Noun	Adjective	Verb	Adverb
poste restante	Yes	No	No	No
annotation	Yes	No	No	No

As nouns, annotation is a hypernym of poste restante; that is, annotation is a word with a broader meaning than poste restante:

poste restante: a notation written on mail that is to be held at the post office until called for (not in the United States or Canada)
annotation: a comment or instruction (usually added)

Other hypernyms of poste restante include notation, note.

poste restante (noun)	annotation (noun)
a notation written on mail that is to be held at the post office until called for (not in the United States or Canada)	the act of adding notes
the part of a post office that handles mail for persons who call for it	a comment or instruction (usually added)