Instruction making rant

[N. W. Perry]

I have absolutely no idea. I've never fully understood how it works.
The way I describe it is my interpretation.

Only recently I discovered the usage of other letters the A for a buffer (see my showcase model for the Telehandler)

So I guess you can put it the way you say too. No clue however.
Maybe someone can enlighten us?

Yep, buffer exchange and rotation matrices—the two holy grails of LDraw. ;-)

I have a specific use case in mind for buffer exchange, in fact, based on a recent convention in official building instructions. The habit these days is to show a sub-build of a model as part of the main step sequence, rather than a series of sub-steps. So for several steps in a row, the main model will be hidden while the sub-build is constructed, then the last step in that group will be placing the sub-build where it belongs in the main model.

So I'd like to work out how to achieve this in buffer exchange, which I assume is just a matter of using the CLEAR meta right after the first STORE command. (I should note that I don't actually create instructions; rather, I try to replicate the build process in the model file itself.)

EDIT: Actually, I guess not—LDCad doesn't seem to recognize the CLEAR meta. Instead, you'd put the STORE command at the very top of the model, before anything's added. Then once you get to the sub-build, you'd first STORE the build so far into a second (B) buffer), then insert a RETRIEVE A command to bring back that first (empty) build state.