My young female boxer (in red) sparred against a girl (blue) whose coach teaches her to cover her head with her gloves, and then bump her opponent using her glove-covered head.
I say that it's still a head butt, whether or not the gloves make first contact.
Here's an example:
https://youtu.be/gX9I8bRn10w
Bumping your opponent (video)
Re: Bumping your opponent (video)
No bumping... no pushing... no shoving... no forearms.. no elbows... no shouldering.. no head-leveraging or head-work... no pushing, pulling or controlling with hands.. no holding.. no wrestling.. no leaning your weight on the back, head, shoulders, or neck.. no hammer blows or Karate chops.. no back-fists.. no low blows... no punching to the back of the head... no punching on the back... no punching after the bell... no palming.. no thumbing.. no striking with any part of the glove but the end of the fist.. no kneeing... no kicking... no pelvic thrusting.. no running.. no stalling.. no grabbing the ropes.. no leaning out between the ropes or stepping outside the ropes.. no talking.. no head-butts.. no unsportsmanlike conduct.. no turning your back.. no bulling in with your head down.. no stopping in the middle of a round to do jumping jacks or other calisthenics.. no spitting or biting... no singing, whistling, making fart sounds or other vocal noises
That should cover most of it.
That should cover most of it.