Settinggroup for Showthread

[evenmonkeys]

A specific question followed by a general question.

Firstly, what's the settinggroup name for "Thread Display Options (showthread)" in the administration control panel? Rather than making an entire page for one single option, I'd rather just tack it onto the bottom or something of that page.

The more general question: where would I be able to find setting groups for future reference? Is there a specific place where they might be listed? Or would I need to dig for it with every type?

Thanks!