Technical rabbinic text question

So does anyone know anything about the prohibition on writing down halachot / writing down the oral Torah? Behind the cut is deeply technical stuff, and I'm sufficiently confused about it that I don't think I can explain if you can't follow my description. But there's quite a few people reading this who are likely to know more about the topic than I do, so I'm posting about it to ask for help.

( religious nerdery )

Help?