Instrument cluster indicators - what are these things for??

[jocko]

Ok, I'm admitting complete buffoonery here, but I've never seen them come on (maybe a good thing) and I have no idea what they indicate...

In the pic of a full gauge instrument cluster - what are the little lights for that I've circled in yellow?

Here's why I'm asking. I've cruised around town wondering what that smell was that reminded me of some idiot smoking his parking brake by driving around town in with his parking brake on (what I moron!!)... OK, yes, it was me. So, as necessity is the mother of invention, I decided on a slick (ok, I think it's slick anyway) way of rigging up a parking brake indicator since my truck doesn't have one. And it will make up for senility, apparently. Then I noticed these lights, so wanted to rule out a factory option I just didn't know about (i.e. parking brake indicator in the gauge cluster?? or maybe they're something else). I can't find a parking brake switch anywhere (and have already started using an extra brake light switch to rig this puppy up - still in work,. maybe a thread to follow - but I think it will work out pretty good) but then I kept wondering about these 2 lights. I assume there are not blank spots for idiot lights in a full gauge cluster, but I've found weirder stuff on this truck already... (by the way, it's not my dash in the pic, but mine's the same)
thanks!
jocko