Why is BN weak?

Fri Jan 2 04:43:16 CST 2015

> From: Julian Bradfield <jcb+unicode at inf.ed.ac.uk>
> Date: Fri,  2 Jan 2015 09:23:59 +0000 (GMT)
> 
> I've been perusing the Bidi Algorithm, and I am wondering why the
> Boundary Neutral class is classified as a weak class rather than a
> neutral class. Can somebody explain?

Because they should take the direction of the surrounding text, I
presume.

What bidi type did you expect them to be?