There are 5 large clouds specifically targeted by c2d, each with off-cloud associated data. The off-cloud regions are near their companion cloud, and are used as calibration/comparison fields. The 5 cloud root names are: CHA_II (ChamaeleonII), LUP (Lupus), OPH (Ophiuchus), PER (Perseus) and SER (Serpens). Off-cloud regions are refered to as "OC" followed by a counter (from 1 to 8), indicating the number of associated off-cloud regions observed.

This list of cloud/off-cloud regions, along with the positions of the cloud and off-cloud centers, is given in the table below. Note some clouds are broken up into segments. Segments are indicated a number of ways following the cloud root name: a roman numeral, the string "north" (north region of the cloud), the character "W" meaning west region of the cloud, the character "E" meaning east region of the cloud, associated astronomical object name such as "L1688" and the word "ALL" indicating the entire cloud (if segments were observed). Catalogs, mosaic images, quality text files, and extinction maps for each of these clouds are available for download ( CHA_II, LUP, OPH, PER, and SER) and can be identified from their file names using the Cloud Names listed in the table.