a maxim adopted as an expression of the guiding principle of a person, organization, city, etc.

a sentence, phrase, or word expressing the spirit or purpose of a person, organization, city, etc., and often inscribed on a badge, banner, etc.

noun

adage , aphorism , apothegm , battle cry , byword , catchphrase , cry , epigram , formula , maxim , precept , proverb , rallying cry , rule , saw , sentiment , shibboleth , war cry , watchword , wordnotes:a motto is a short phrase that usually expresses a moral aim or purpose; a slogan is a catch phrase used by a political party or other organization in advertising or promotion , saying , call to arms , call to battle , axiom , banner , catchword , epigraph , expression , phrase , principle , quotation , slogan , truism