Question: Quotation marks or italics? His last words were "clock" and "good-bye." Clock and good-bye are used as words and are not quotations, but they are not unusual or in need of emphasis so I don't see the reason for italics. If the answer is personal preference, is one choice more popular, more formal than the other? I could not find a clear answer on here so I thought I would ask. The English Usage Stack Exchange site is amazingly useful. Many thanks to all who contribute.

Answer: 
It depends on whether you are describing reported speech or word used as words. The first uses quotations, while the second is either underlined or italicized, to differentiate it from reported speech, according to both the Chicago and MLA style manuals. There's a subtle difference between the two usages, where the first is journalistic while the second is more like a dictionary reference.
Of course they are *quotations*, that's the definition of "his words were"