This was really confusing to me, and I had to go looking through the Tab
history, where I found a comment explaining it that has since been
deleted. This wasn't a great experience.
This commit basically adds that explanation back in.
This is the (partially) documented public API for Homebrew.
The main class you should look at is the {Formula} class (and classes linked from there). That's the class that's used to create Homebrew formulae (i.e. package descriptions). Assume anything else you stumble upon is private.