Sentence:  [Bertie Wooster:] “Right-ho,” I said, not much liking the assignment, but liking less the idea of endeavouring to thwart this incandescent aunt in her current frame of mind. Safety first, is the Wooster <WSD>slogan</WSD>. 
Meaning of the word marked with <WSD> tags:  A distinctive phrase of a person or group of people.