Thanks for your help.

When I call into AT&T "Terminal hunt" is the term they've been using when we talk about what we have set up. That's why I repeated it here.

I'm still confused though. Is there anyway I can achieve the following? Ideally, this is how I want the lines to work:

1. Outgoing calls made on all three lines will show up as coming from 1321. (This is currently working.) (As a reminder, we only have the 1321 number now. Lines 2 and 3 do not have their own dedicated phone number.)

2. Line 1 (1321) has priority. Calls will always start to ring on this line if it's open.

3. Line 2 has second priority. Calls will only ring here if Line 1 is busy.

4. Line 3 has third priority. Calls will only ring here if both Line 1 and Line 2 are busy.

Items 2-4 are not currently working this way.

So, is there some way to accomplish what I'm seeking? If so, what do I tell AT&T that I need? When I've spoken with them, they don't seem to understand.