RTE.default {
contentCSS = fileadmin/templates/css/typo3-RTE.css
}

RTE.default.proc.allowedClasses := addToList(tel, fax)
RTE.default.buttons {
     textstyle.tags.span.allowedClasses := addToList(tel,fax)
}

RTE.default.proc.allowedClasses := removeFromList(csc-frame-frame1, csc-frame-frame2, important, name-of-person, detail)

RTE.classes := removeFromList(csc-frame-frame1, csc-frame-frame2, important, name-of-person, detail)

 RTE.classes.tel {
     name = Telefonnummer
         class = tel
 }
RTE.classes.fax {
     name = Fax
         class = fax

}