How do I enable YACC only for certain branches?

Sometimes, it’s useful to turn on checks only for certain branches, and turn it off on all other branches.

YACC has a related feature, “Exclude Branch Regex”, to specify a regex that can exclude branches from checks. With a little bit of regex magic, this feature can be used to only run YACC on a set of whitelisted branches.

For example, if you want to do checks only on the branches master and release, but no other branch, configure the "Exclude Branch Regex" option like this:
^(?!master$|release$).*

All branch names other than master and release will be excluded, and thus the checks will only apply to those two branches.