Means three different things.

1. A clandestine greeting used by those in the KKK. 3 x the 11th letter of the alpahabet.

2. Gang greeting and sign used by the Bloods. 3 = c, 11 = k or Crip Killer.

3. 3 1 1. police code for indecent exposure.

I think acl65, which is also a code for the "Candair regional jet," meant to say 4 1 1, the common # for information.