Wow! I found a web page that provided around 192 possible meanings for the abbreviation AF. The small amount of context provided rules out Armed Forces and Air Force (two very big users of project management).
My experience tells me Award Fee from contracts, but you haven't provided enough context to be sure and I haven't read all the possibilities. Its quite likely this was a government document since some government agencies (US) are well known for using this contract type.
The award fee is the amount of payment that is provided upon contract award, possibly to be used as seed money or as a form of incentive for the project.
If you can provide just a little more context, it would be helpful.