Traditional. Nuzlocke rules are very simple.
1. The only Pokémon you can catch is the first one you encounter en route, aside from duplicates (only after obtaining pokeballs, obviously),
2. If a Pokémon faints, it is considered "dead" and must be released, or put in the PC indefinitely.
For some other "optional" rules, and even amendments/clarifications to the rules, check out the page on. Bulbapedia on it.
http://bulbapedia.bulbagarden.net/wiki/Nuzlocke_Challenge