5 FONT_IT (* IT default, may be forced to be RM *)
6 | FONT_RM (* RM default, may be forced to be IT *)
7 | FONT_UF (* not affected by IT/RM setting *)
8 | FONT_RTI (* RM - any, IT - not available in HTML *)
9 | FONT_UFH (* in TeX UF, in HTML RM *)
15 HTMLABLEC of font_class * string * string
16 | HTMLABLEM of font_class * string * string
17 | HTMLABLE of font_class * string * string
18 | MHTMLABLEC of font_class * string * string * math_class * string
19 | HTMLABLE_BIG of string * string