Here are a few possibilities:
* Air Force One (AF1): This is the most common association. AF1 is the call sign for any U.S. Air Force aircraft carrying the President of the United States.
* A specific model or part number: AF7 could be a model number for a product, a part number, or a code used within a particular industry.
* An abbreviation: It could be an abbreviation for a phrase, a company, or an organization.
To understand the meaning of "AF7," you need to provide more context. For example:
* Where did you see or hear "AF7"?
* What was the context of the conversation or document?
Once you provide more information, I can give you a more accurate answer.