Not all that many calls received per my Caller ID, however I'm always suspicious when the caller is identified as "Private Caller". I called the number, got an automated response that informed me the call I got was not of an urgent nature, identified themselves as "SWA" and gave me a chance to leave a Voice Mail. I left a VM giving my name & phone number, asked to be placed on their Do Not Call List, & that I did not know who SWA was. Since this is a local number for me, I did research my yellow pages a bit. I did not find any separate SWA, though there are a ton of "Southwest" something or others. Most obvious would be Southwest Airlines, but there were other possibilities. SWA Googled got the same kind of results. Nothing confirmed.