It would be helpful if you could tell us who made them because the instructions are different depending upon the content creator, but my hunch says these are Jointed Rail's Safetran signals and CL means Colored Light. Jointed Rail does have some signal information to download on their website if I recall. It's been awhile since I went looking there for that.
With that said, Jointed Rail uses a simple system.
Type 01 and Type 04 = Absolute signals, meaning like stop signs and are found where tracks come together or at entrances into other lines such as a yard lead on to a main line, siding, etc.
Type 05 = Permissive, advanced, aka home signal. These will have a black bar below where a signal number can be placed. Older ones will have the default signal name emblazoned across the bar, i.e. Signal 1234567890.
Type 06 = Diverging. These are two-headed signals used when tracks come together.
Type 06d = Distant signal. These are advanced signals used to warn drivers of upcoming junctions and repeat the signals that the driver will be approaching. In real life, the driver now knows to slow down for the upcoming junction, meaning track split from single to double track, yard ladder, etc.
Type 08 = Interlocking - used for crossovers and wyes.
Any signal with an L will mean left side of the tracks; R will mean right side. Some signal designations mean the signal will indicate left-moving direction by default even if the signal is on the right. The name, as I've seen in the past is similar to this Type 06L (right side).
Show advanced approach aspect will be an option for the Type 05 permissive, which is also and advanced signal. These work by showing what's coming up so that the engineer can prepare for the track ahead. With an upcoming red-signal, the Type 05 will show two different kinds of yellow lights. The first Type 05, some miles away will show a blinking yellow. The following Type 05 will show a solid yellow, and this is to tell the engineer to drop to 1/2 the posted speed and prepare to stop at the next signal.
Approach lit is obvious. You can have signals turn on when the train arrives within the "circuit" for the track. I have never used that option.
Automatic means the signals work as they regularly do in Trainz. There's no need to intervene, and they will perform without the other operations. Type 05s and Type 04s are usually the ones with that kind of operation, and generally the others work similarly just as well.
Setting up these options, from what I remember, has to be done now in the session and not at the time that the signal was placed on the route. This is a pain in the backside because it's not only a double-task, but it's also risky because if the session gets corrupted, all the signal settings are lost.
