You tend to build some incredibly useful (if not brilliant) functionality into your software, and then seem to forget about it.
But is it documented?
I do tend to forget features I add, it's true.
Thankfully yes, it is documented. That's the key isn't it -- to document these things as they are added.
From the help page on "Special Search Modifier Keywords":
show all matching results, bypassing the normal limit on result count+alias
match search only against aliases
do not show any matching aliases (only files)
do not give bonus scores to items in history
do not show any files, only folders (and aliases)
do not show any matching folders, only files (and aliases)
show matching folders
as soon as there is one (alias) result in the result list, launch it.