blackhawk started their line of holsters for primary use of LEO's and Military applicaitons ONLY. shortly after they started marketing their holsters to the civilian public after MIL and LEO's started asking where they could buy one. some moron in marketing put "serpa CQC CONCEALMENT" on the package. however it is very hard to "conceal" these holsters unless your "urckle" your pants and wear a long shirt, then it is possible to conceal the holster mid-torso with your arm.
however they suck as concealment holsters. i've tried every single way possible. good for OC. bad for CC.
IWB *in waist band* or pancake holsters are the best for concealment. IWB holds the holster and gun inside the waistband of your pants, concealing 80% of it for you, all you have to worry about is the handle and 5% of the backstrap.
Pancake holster ride OWB *outside waist band* on your belt. you will usually see police detectives using them on NICS or CSI. its thin leather, and pulls the gun very close to your body, therefore somewhat concealing. it is more compfortable than IWB as well.
good pancake brands are "strong" leather, "galco" and even blackhawk makes some good ones
IWB, Galco king tuck 2, Kangaroo holsters, or Crossbreed are also great, although kangaroo is not a IWB instead a vest you wear under your shirt.