Just to add to what Aaron was saying about BCI and BCC's...
The difference between BCC's and BCI's is that they are divided by altitude and locality (the Andes)
BCI originate from Mexico, Central American countries and down into northern Colombia
BCC are east of the Andes: Central and Southern Colombia, Peru, Bolivia, Brazil, Guyana, Surinam, Venezuela, and Trinidad.
BCI have more dorsal saddles or blotches (CAN BE as low as 19, but usually 21+)
BCC have less (sometimes 21, but usually less than 19)
BCC's tend to grow larger and are somewhat more heavy bodied than the BCI's.
Some BCI may have red in their tails but it is nowhere NEAR as vivid as what the BCC's are known for.
And Finn, in regards to still thinking it's a "Red Tail", that actual term is more of a pet store term to generate a sale, Red Tail Boa has been used in pet stores for a while regardless of what Locale the actual boa is. Although 9/10 when I see a "red tail boa" in a pet store, it's your common Colombian Boa Constrictor Imperator (BCI).
Hope this adds some clarity to the "who am I" thread hehe