Is there a simple example script showing how to import users and posts into Vanilla from another (in my case, file-based) forum?

I've seen the phpBB import script that was mention here, but I wonder if there is a clearer official docs/example that shows how, and what is necessary, to create users and posts, either directly in the mysql database or maybe by calling the internal Vanilla functions?

I guess I could work it out for myself by trawling through the code/database structures, but it would be great to have some definitive docs/example on e.g. which of the many SQL fields are necessary to set when you create a user or comment.