There are lots of schematics of minecraft circuits online, but few of them reference the notation they are using and I am finding it hard to chase down what some symbols mean.
The page on Advanced Redstone Circuits references the MCRedstoneSim format. The most recent version of that is 13 January 2013. It does not contain symbols used on many minecraft schematics.
For example Layer 0 of a shift register here:
has squares with grey and red/grey triangles in them. I have no idea what they are supposed to be.
On the wiki itself there are weird triangular things as well, for instance a diagram of an edge detector (http://minecraft.gamepedia.com/Pulse_circuit#Edge_detector) has things I don't understand in it.
Is there a reference for these notations somewhere? (I am trying to make a simple 2 bit shift register as it happens).