These are the current requirements for getting your code included in RF24:

Try your best to follow the rest of the code, if you're unsure then the NASA C style guide can help as it's closest to the current style.
Definitely follow PEP-8 if it's Python code.
Follow the Arduino example formatting style for Arduino examples
Add doxygen-compatible documentation to any new functions you add, or update existing documentation if you change behavior
CMake modules and CMakeLists.txt files should also have a uniform syntax.
- Indentation is a mandatory 4 spaces (not a \t character).
- Closing parenthesis for multi-line commands should have the same indentation as the line that opened the parenthesis.
- For other useful CMake syntax convention, please see CMake docs for developers and this useful best CMake practices article. The qiBuild project has some well-reasoned "Dos & Don'ts" guideline, but beware that the nRF24 organization is not related to the qiBuild project in any way.