Radio connector question

[67HEAVEN]

After removing the stock 1989 Silverado AM-FM-Cassette unit, I saw the stamped pinout information on the case about the various connections, like, speakers, etc.

What do the following refer to?

P-LT (beside the terminal marked GROUND)
DIM (next to P-LT on one side and Antenna on the other)
ANTENNA (next to DIM on one side and IGNition on the other)

P-LT? Panel light?
DIM? Something to do with dimming the dash lights including the radio?
ANTENNA? The radio has the typical large antenna connector away from the electrical connectors, so why the extra pinout marked antenna?

Thanks.

[tubbedII]

DIM is so when the headlights turn on, the radio dims so it's not so bright since it's dark out. Some also tap into the dimmer switch so the dimmer also dims the radio brightness.

ANTENNA is for a power antenna, it tells it when to go up and down

I have no idea what P-LT is, the most I came up with on the web was something about the parking lights being off, but I don't know what that does on the radio...

[67HEAVEN]

Thanks tubbedII. That was helpful.