Is there a law against using the acronym for an organization or an event in an outside party's advertising? Does enclosing the acronym in quotation marks, or other punctuation, permit an outside party to use the acronym in advertising?
Example: Organization Event: North American Prospect Expo. Commonly referred to as NAPE. Is there a law against using NAPE in third party advertising?

Typically the way these things go is that if it is clear you are referring to a protected name, it is in violation. Cases like these are always best to get permission before doing anything. Saves on legal fees after the fact.