Syntax of RTAddressRegexp

I’m using RT 3.8.8, and am getting warnings about the " RTAddressRegexp option is not set in the config".
If I understand correctly, I don’t need to worry about it since I never plan to have any queues set up to auto respond with an “On Create” scrip. But I still see the messages in root’s email and on startup. So, I thought I’d set one up. After thinking over a regex to cover everything, I came up with the need to search for an address beginning with (ie):

shark, catfish, dolphin
(so, shark-head, dolphin-tail, are possible)

and the domain can be:

Would something like this be right:

Set($RTAddressRegexp, ‘^(shark|catfish|dolphin)@.(water)?($’);


Any help would be great.