ReloadUI(string guiName) - what are possible guiNames?

[zgrssd]

According to the Wiki documentation ReloadUI takes a string parameter. But there is no details, in particular:
What would this do? Allow only part of the UI (like the Chat Window) to be reloaded?
What are possiblke values? Found nothing by seaching through the Globals on the Wiki.

[Seerah]

I don't know. ReloadUI() is defined C-side.

Though the reload ui button on the addon window in-game and the slash-command function both take the "ingame" parameter.

ReloadUI("ingame")

Those are the only two places I see the function used in the UI.