The (A) means that the switch is NOT in it's resting state, and that it is currently Active (note that the word Active start with the letter A, it's like Sesame Street).

You should also notice in single switch test that the sound is different for switches that are stuck on when you get to them, thus you know when you get to a bad switch, because the sound is different.

If it's a loop switch, and there is no ball in the switch, and it's marked (A)ctive, then it's stuck ON (or OFF if it is an opto).

I almost said closed, but you'll notice that some switches are closed normally, and some are open normally, they are in their non resting state when the (A) is present, thus why the (A) is there in addition to the closed or open statement. OPTO's are normally closed and go open to be active, most physical switches are normally open and go closed to be active.

As an added bonus, while you are in switch test, hit the start button, you'll get three pages of information on the DMD; everything from the wire colors, transistors, chips, connectors, and fuses that that part goes through to get to the processor (it works on lamps and solenoid tests too.)

_{Post edited by themadman: Take out rant on people not knowing how to use basic tests...}

It was late, and I dealt with what seemed like dumb question day at work, so I vented a little.

Looking at the WPC manuals, it's not documented. I guess Williams expected you'd figure it out when you went to test a switch... I suspect the reason the (A) was added is so that the switch level test (which only shows Active switches in WPC and up, but shows closed switches Sys11 and down) and the tech could figure out when the switch was active, since closed no longer means active (especially on an opto).