position paper vs memorandum

position paper and memorandum both are nouns.

Word	Noun	Adjective	Verb	Adverb
position paper	Yes	No	No	No
memorandum	Yes	No	No	No

As nouns, memorandum is a hypernym of position paper; that is, memorandum is a word with a broader meaning than position paper:

position paper: a memorandum summarizing the items of an agreement (used especially in diplomatic communications)
memorandum: a written proposal or reminder

Other hypernyms of position paper include memo, memoranda.

position paper (noun)	memorandum (noun)
a report that explains or justifies or recommends some particular policy	a written proposal or reminder
a memorandum summarizing the items of an agreement (used especially in diplomatic communications)