Well considering all of the letters except npw are capitalized I would say that  the regex is something along the lines of

EDIT: Forgot the $ at the end lol.

EDIT2: It seems the regex done by vanitygen is actually different than regex done by Ruby or PHP. The above regex or even the below regex both only match patterns like your address when done in Ruby or PHP but VanityGen seems to return strings with lowercase letters other than npw even though its not allowed by the regex.


In ruby/php out of these addresses, address 1 and 3 are found and address 5, 6, and 7 are addresses that were found by vanitygen but are not matched when added to the ruby/php list to check.