The L flag

[Pheotis]

L gates centre around the presence of one or more chiselled bookshelves.
Destinations are determined by the contents of said bookshelves.

Right-clicking a book on a gate associates that destination to the book.
The presence of the book in the bookshelf adds that destination to the portal.

This ignores networks, and functions as non-static fixed portal.
I.e. if the user has perms to get to that gate, regardless of network, they can select it through an L gate.

Left clicking a book in the shelf could possibly select the associated destination.