cue sheet information source?

Lisa's question brings something up: is there a source on line for learning
about cue sheets and what they can accommodate?  I've seen lots of cue sheets,
but to learn how to write one from nothing but completed examples is backward
reasoning that's incomplete.  They allow a lot of features that are never in
those examples, and seeing only finished products raises more questions than
it answers.

What I need now is some ground-up explanation rather than yet more top-down
dissection.  I want to learn how to write them, not only how to read them.

Whenever and wherever I have asked that question, the only responses have been
copies of cue sheets to read (most of which the senders didn't write
themselves and can't answer questions about anyway).  That isn't what I need
at this point.

Thanks for any assistance.