Numbers in Indian reserve names

It seems most Indian reserves in Canada have one or more numbers, and sometimes letters as well, at the end of their names. Some examples:
[ul]
[li]Blood 148[/li][li]Ahtahkakoop 104[/li][li]Moose Lake 31A[/li][li]Tsinstikeptum 9[/li][li]Stoney 142, 143, 144[/li][/ul]
What’s the significance of these numbers? They aren’t unique (there are several reserves with the number 1, for example, even within the same province). Also, not every Indian reserve has a number. How come most have numbers but some don’t?

Anyone?

Could they be band codes or reserve numbers? (From an “Indian and Northern Affairs Canada” page of definitions) I’m not Canadian, sorry, so that’s just a random guess.