Here is some good reference reading material about the subject.
Feel free to post and share more references.
1.
SKYbrary - Circling Approach - difference between ICAO PANS-OPS and US TERPS
2. Jeppesen Introduction - Glossay - Aircraft Approach Category
3. ICAO DOC 8168 vol 1. can be found in the Jeppesen Airway Manual (see Table I-4-1-2 as a starting point and explore around it)
4. FAA AIM 5-4-7 a. (page 5-4-26):
http://www.faa.gov/air_traffic/publi...c_2-9-2012.pdf