assert, ipairs, and next appear to exist as in stock Lua, but the manual doesn't mention them (outside of the changelog). It does mention every other supported Lua built-in, so this omission makes it harder to gauge what exactly is still exposed (especially without access to _G). Especially odd since the coroutine documentation mentions wrapping coresume inside assert.

Also, the select builtin is documented (indirectly, under Function Arguments), but doesn't seem to exist! At least not in 0.2.0h.

The ? unary prefix operator is also not documented, though it's used in a couple examples.

While I'm at it, in the section on code limits:

"Right click to toggle through other stats (character count, compressed size)."

That should be left click.