guideline vs guidepost

guideline and guidepost both are nouns.

Word	Noun	Adjective	Verb	Adverb
guideline	Yes	No	No	No
guidepost	Yes	No	No	No

As nouns, guideline and guidepost are synonyms defined as:

guideline and guidepost: a rule or principle that provides guidance to appropriate behavior

Other synonyms of guideline include rule of thumb.

guideline (noun)	guidepost (noun)
a rule or principle that provides guidance to appropriate behavior	a rule or principle that provides guidance to appropriate behavior
a detailed plan or explanation to guide you in setting standards or determining a course of action	a post bearing a sign that gives directions or shows the way
a light line that is used in lettering to help align the letters