hashmark vs service stripe

hashmark and service stripe both are nouns.

Word	Noun	Adjective	Verb	Adverb
hashmark	Yes	No	No	No
service stripe	Yes	No	No	No

As nouns, hashmark and service stripe are synonyms defined as:

hashmark and service stripe: an insignia worn to indicate years of service

Other synonyms of hashmark include hash mark.

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