Flaws in the BBCode 1.0 specification

I have noticed that people use [sub] where something like [small] was meant. The Shiichan implementation of BBCode 1.0 doesn't cover [small], which is kind of annoying.

We should design the 1.1 specs, since this effort looks like abandoned^[1]. Post all your proposals here. Particularly, IIRC, someone requested some LISP-like features. A formal description of such improvement would be nice.

^[1] http://wakaba.c3.cx/shii/

iirc the shiitchan software already uses an external library for bbcode, if a spec is written i can write a replacement as an implementation of BBCode 1.1.