Man pages matching name xtregisterdrawable in section 3:

XtRegisterDrawable.3.en	debian 10 / libxt-dev
XtRegisterDrawable.3.en	debian 11 / libxt-dev
XtRegisterDrawable.3.en	debian 12 / libxt-dev
XtRegisterDrawable.3.en	debian 13 / libxt-dev