https://manpages.ubuntu.com/manpages/questing/man6/xbevel.6.html
Ubuntu Manpage: xbevel - Bevel X widgets
ubuntumanpagebevelxwidgets
https://manpages.ubuntu.com/manpages/resolute/man6/xbevel.6.html
Ubuntu Manpage: xbevel - Bevel X widgets
ubuntumanpagebevelxwidgets