Actually, the Complex component to C-PTSD does in effect, stand for chronic because complex trauma means that the trauma was either long term (meaning chronic), or, multiple individual traumas layered upon each other. At least, that's the way I understand it.
If you go to the U.S. Department of Veteran Affairs, they have a good deal of information on the topic. I read that C-PTSD is finally going to be included in the next DSM that is coming out in, I think, 2015. Clinicians find that the Dx of PTSD doesn't quite capture the full set of symptoms and effects of long term trauma.
While a treating provider can't officially use the Dx of C-PTSD yet because there is no code for billing and insurances purposes only, many still use it in their patient's chart notes and explain it as being the Dx for said patients. For now, they typically use DESNOS- which means Disorders of Extreme Stress not Otherwise Specified- for billing and insurance purposes.
Many examples of situations that warrant the C-PTSD Dx are:
Prisoners of war
Prisoners of brothels
Long term child abuse of any kind
Long term victims of domestic violence
If you type CPTSD in google, you should be able to find the link for U.S. Department of Veterans Affairs information on C-PTSD.