That is, when would it be preferred in a rescue situation to carry someone using a Bridal Carry (warning TVtropes) a la princess style over other methods like the Fireman's carry or Over the shoulder carry? (Tvtropes warning)
I can find some stuff on why Bridal Carry is a bad idea, although nothing that is actually authoritative. I also can't find any information on whether Bridal Carry can be actually useful in any situation (other than for romantic overtones). I did find this bit via Google cache but the method describes...more of a caveman/over the shoulder carry, I think, instead of the traditional Bridal Carry.
Search terms: "Bridal carry", "Princess carry", "Bridal Carry use", "Bridal Carry rescue"