I came to Github to create an issue asking for the FQBN for an Arduino Nano with the "old" bootloader. Luckily I was able to find it in an old issue.

I'm working on a similar project which is a simple Makefile wrapper of the Arduino 1.5+ CLI commands. My question is, what is the proper way to track down the FQBN of a given board, and any potential CPU flags for variants?

I'm happy to come here and post an issue every time I run in to one, but that puts more work on you. Is there documentation somewhere that talks about FQBNs? Is there a way that I can read them from the IDE preferences?