What are the numbers for?

[dan d.]

What are the little white numbers for that you see on some rail systems like the Knight Armament and Surefire? Here is a rail system for example its under specials and its the Surefire M63 .

http://www.eliteguns.com/index3.html

 

[RoverDave]

Isn't it just for reference so that if you take an accessory off you can get it back on in the same spot easily?

 

[chrisp929]

yep

 

[dan d.]

I thought it was going to be something more complicated than that. Thanks guys.