https://core.tcl-lang.org/bwidget/brlist

The GitHub mirror's master branch is the Bwidget Source Code trunk branch.

It might be considered to make the mirror default branch bwidget, and after that rename the then no longer default master branch to trunk. That being said there's the circumstance that the mirror's bwidget branch is 155 commits ahead of, 49 commits behind master; which for obvious reasons shouldn't be overlooked were reseting the mirror's default branch and any branch renaming pursued.