The ratings your talking about are not coax specific so that might be what's messing up your google fu. Here are a few links to get you started.

https://www.cablewholesale.com/support/technical_articles/cable_ratings_and_materials_and_counterfeiters.php

http://communities.leviton.com/thread/3792

http://www.lanshack.com/pdf/PlenumVsRiser.pdf

In researching coaxial cable ratings I'm running across multiple conflicting resources. For example: CMR seems to suggest the cable is riser-rated, yet I find bulk coaxial on Amazon, marketed as in-wall rated that is only CM. Where might I find more official documentation or charts to learn these various designations and their appropriate applications?

Understanding the coaxial rating system