Template talk:Place
Slot 1 (BAMC): The text that will be clickable.
Slot 2 (San Antonio, TX): The display text that isn't linked, and also helps the map search.
Slot 3 (The URL): If you put a link here, BAMC becomes an external link (with the little arrow icon). If you leave Slot 3 empty, it stays a red (internal) Wiki link.
The Map: It still combines Slot 1 and Slot 2 to make sure the Google Map points to the right place in San Antonio.
The Wikipedia "W": Using w:PageName is the standard way to reference the "Big Wiki" without cluttering your local database with pages that already exist globally.
The #pos Function: This looks for the position of "http". If it finds it, it knows to use the external link format.
Map Search: Note that I updated the Google Maps link to the official api=1 format. This ensures that even if you link to Wikipedia, the [map] link still correctly searches for the physical location.