In terms of pattern, it's super easy. It's 3 rows, with a two stitch pattern per row.
You'd think it would be easy peasy, but noooo!
I mean, try it. Count one, two, one, two, for about 200 stitches. You can see how easy it would be to get a "one, two, two," in there.
My rows are about 500 stitches at this point I estimate, and I've tried starting the Brioche stitch twice now, and screwed it up both times! The first time it was such a mess I had to rip back four rows!! Four!! This time I've just left it. I'm not sure what to do. Hopefully I'll only have to go back two rows. Still. It's bloody painful!
And it really doesn't help that it's very hard to see where you've screwed up. It's the nature of the stitch, it looks fine until you get to knitting it the second time around, then you realise it's not right at all, and you've messed up the "one, two, one, two" pattern.
I think I'm going to leave the damn shawl for a bit and come back to it. I just can't bring myself to rip out the two-four rows again. Gods help me! It looks like such a simple stitch.....