EIC Pistol Matches, Service gun requirements

I shoot NRA/CMP High Power matches for the most part using a AR Service Rifle. So I have a pretty clear knowing of what can and can't be on/in a rifle to classify it as a Service Rifle.  I'm stumbling around attempting to get information to what are the requirements of a CMP EIC Service Handgun... If there is such a beast.  I think I'd like to try my hand at  Bullseye shooting and use a 1911 in 45acp of which I'm somewhat familiar and comfortable shooting.

I've perused thru both the NRA and CMP rule books (pistol) and I'm not real clear on what can and can't be on the handguns (or what handguns) to make them "legal" for CMP EIC Service Handgun shooting.

Thanks for any help.

The rule you are looking for is 4.1.1 Service Pistol (page 36 of latest rule book as seen here
https://thecmp.org/wp-content/uploads/2024/01/2024-Pistol-Rules.pdf

CMP has three (four if you count air, but in a different rule book) distinguished badges for pistol 
-Service Pistol 
-Rimfire Pistol 
-Service Revolver

These are all covered under rule 4.1 CMP National Trophy/EIC Pistol And Revolver Rules