Meanderings

Anyone know how to make a list online that is of the style 1.1; 1.2 etc.. I'm doing the AHGTC competition rules, and they are numbered, e.g.
1 General rules
1.1 x
1.2 y
2. Other rules
2.1 z
And so on. Best I can do so far is a bullet point and writing in the number after, but the alignment looks bad. *sigh*
I can do <ol type="x">, but I can't seem to find one that will let me do different types of numbered lists... i, ii, iii etc., but not 1.1; 1.2 etc.

Help!