[whatwg] Comment on Forms 2.0: OPTGROUP Nesting

[levik]

I think the web forms 2.0 spec should include support for nesting
OPTGROUP tags inside of a SELECT element. Current OPTGROUP
specification for some reason limits grouping to one level, which
allows UAs to implement it in a fairly useless way (by inserting a
non-selectable line item into the menu)

Nesting OPTGROUPs would allow hierarchical menu structures to be
implemented for single-line SELECTs, and tree-like structures to be
shown in multi-line select (ones with SIZE="x").