Whats up with the menu data type for SOCs?

So I was reading the article about SOCs on the SRB2 Wiki when it said that the menu can be modified through SOCs? I've got no clue what it means and the Wiki has no information about the data type. Can anyone give me a basic rundown of this data type as well as a few parameters? Thanks.

I prompted about it in the Discord server, and after some digging around, Monster Iestyn created a new GitLab wiki page with the original documentation about it prior to its implementation.

It's probable that some items are outdated, but here's the relevant information about it: https://git.magicalgirl.moe/STJr/SRB2/wikis/Internal-documentation-dump/new-title-screen-features
There's an example for it in this page as well.

This implementation is about new title screen features: It allows you to change the background (even hiding the title screen logo) and music (and fading them as well) as well as showing screen wipes, and if you're using a titlemap, what linedef tags to execute when entering or exiting the sub/menu.
I may be missing something, but that's the basic rundown for this feature.
It is not about customizing menu items.

Ah ok thanks