DD#1 is a mix invented by Watcher.

http://www.love-scent.com/reference/cookbook.html

The link above has a listing of all the famous mixes and their ratios (toward the middle of the page). DD#1 is 7 parts SOE and 3 parts NPA/m.

Recently, people started using a variation called DD Lite, which is I think 9 parts SOE and 1 part NPA/m, but I\'m not sure. Some people reported good success w/this ratio.