Where is the .THM syntax explained anyway. The OTS standard doesn't mention it and the Litestep Control Panel accessable via Ctrl-Alt-F1 doesn't need it to change themes (at least it doesn't need it to change to my theme and I don't have a .THM).

More importantly, what use does it really have? If an utility incorporated in LS itself can toy with themes with ease without such a file, where does one need a special theme switcher?

lsts uses it for theme information. it can be edited via lsts too.

The LSCP theme switcher is not "incorporated in LS itself", it is an EXE of its own and is not included in the next version of LiteStep (0.24.7). In fact, it never was included in the "official" "LiteStep" at all, it's an Indie LS feature. Its biggest problem is that it deletes $litestepdir$step.rc and completely rewrites it if you switch themes, so anything you put in there is lost. It also lacks many of LSTS' features, such as the preview image. Now before you say you don't need the preview image read the next paragraph...

LS is about choices, and the LS Installer chose LSTS to switch themes. Other distros/standards may choose other theme switchers. That means if you create a theme and want it to work with the LS Installer you'll need to include a proper .thm file in your theme.

About creating the .thm files, as Egonz said, use LSTS.

I am not one of those people that answer with petty excuses for an argument like "I don't need a preview image". :)

And I see, so that's how it is. I've never used LSTS and sincerely doubted the need for one, as I've never seen any need for the root step.rc to do anything but include the theme rcfile.

By the way, will the offical 0.24.7 have any innate means to switch between themes or will it aim to use LSTS?
Standards are good and it's best to know beforehand.