hash mark vs service stripe

hash mark and service stripe both are nouns.

Word	Noun	Adjective	Verb	Adverb
hash mark	Yes	No	No	No
service stripe	Yes	No	No	No

As nouns, hash mark and service stripe are synonyms defined as:

hash mark and service stripe: an insignia worn to indicate years of service

Other synonyms of hash mark include hashmark.

hash mark (noun)	service stripe (noun)
an insignia worn to indicate years of service	an insignia worn to indicate years of service