I think only military ones had that, but I'm not sure.I recall the M1911 I used in the Army having a loop for the lanyard I was issued (I was an MP). As I remember it, the loop was on the butt of the gun though from what I've read, it's sometimes on the magazine. My RIA 1911 doesn't have that loop (butt or magazine). My question: Did only actual military M1911s have that loop, or perhaps some manufacturers, like Armscor, don't include that feature while others might?
You could always buy a mainspring housing that comes with a lanyard loop:
I haven't seen any commercial 1911s that come with the lanyard loop standard.