We bought about $20 worth of stuff from Mouser and they sent us a catalogue that looks like it cost $100 to print. They treated us so well (very few companies would mail an order out to a new customer half way across the country and wait for a check) that I'd like to order some more stuff from them for a project I'm working on and to keep on hand.

I'm looking at double pole double throw rocker switches and I can't seem to figure out whether or not they are momentary.

Some listed like like this:  on - off - on

Others are listed like this: (on) - off - (on)

Some are a combination of the above, or even say "none" instead of "off". 

Now I'm guessing that the parenthesis means momentary? What about the "none"?