What does 'bottle :unneeded' do?

Question

I read Method: Formula.bottle but it's not very clear to me. When writing a home-brew formula, what does the following do?

bottle :unneeded

Answer 1

When a formula you submitted is accepted in one of the official taps, a bot grabs it; builds a pre-compiled version of the formula, and uploads it in some public location. This pre-compiled package is called a bottle and is used to speed-up installation of compiled things.

bottle :unneeded is an indication to the bot that this formula doesn’t need a bottle; e.g. because there’s nothing to compile.

Note that bottle :unneeded was deprecated by homebrew-core in June 2021, and no longer has any meaning to the bottler.