https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87050
--- Comment #12 from Janne Blomqvist <jb at gcc dot gnu.org> --- Based on a recursive grep of the wwwdocs repo the only remaining use of "xhtml" is a variable "XHTML" in htdocs/style.mhtml which, AFAICS, doesn't any longer actually have anything to do with XHTML. A big thanks to Gerald!
