Where can I get information on OpenSCAP profiles?

I went to the link below to get the latest RHEL6 benchmarks for oscap. Here is a list of profiles when I look at the contents of the xccdf.xml file.

Profiles:
MAC-1_Classified
MAC-1_Public
MAC-1_Sensitive
MAC-2_Classified
MAC-2_Public
MAC-2_Sensitive
MAC-3_Classified
MAC-3_Public
MAC-3_Sensitive
Disable_Slow_Rules
CAT_I_Only

http://iase.disa.mil/stigs/scap/Pages/index.aspx

Where can I get detailed information on what each profile means and when it should be used? From what I gather a "MAC 3" has the highest level of security as well as "Classified"? Can someone point me in the right direction to get info on these? There does not seem to be any reference to these on the DISA site.