Unless you’re a scriptwriter, this post probably won’t interest you. I’m a stickler for uniform-looking documents in series: one of the main reasons why I use (La)TeX. Recently, I’ve been writing what are basically ‘design guidelines’ at the beginning of my upcoming coursework publication, Wine Glass Moustache—don’t ask—so, when proofreading it, I have a definiative solution to common problems like how to arrange radio scripts if they’ve got timecodes, or how to cite people’s quotes rather than their publications (in these cases, an omiliography is what I’m after). Today, I’ve been musing on what interruption mark to use; an interruption mark is something put at the end of a line in a script to indicate an interruption. For example, …
KS: I think all religions are, in practice, cul-
JE: Stop right there.
In the above example, I’ve used the hyphen to denote an interruption to my (KS) lines; I think this is the mark I’m going to stick with. Alternatives were things like ellipses, but then the line looks incomplete:
KS: But they are. Just ask the OED: it defines ‘cul…
It looks like I haven’t finished writing the line, at least to me it does—kind of like a programmer’s TODO. 
I think I’m going to stay with the hyphen but I’m interested to hear what you think, not just on boring bollocks like how to write interruptions in scripts. Do you have your rules of writing written down?; is it so you don’t waste time having an internal conflict with opposing brain halves?