[css3-break] Limiting break propagation to the fragmented flow

Section 4.1 notes that:

---
Since breaks are only allowed between siblings (1),
not between a box and its container,
a Œbreak-before¹ value on a first-child box
is propagated to its container.
Likewise a Œbreak-after¹ value on a last-child box
is propagated to its container.
---

First, the (1) isn't clear to me - I'm assuming it refers to the mention
of 'siblings' in the Class 1 definition above.

Second, I think there should be one more sentence that notes that this
propagation stops at the fragmented flow boundary. If the first child of a
multicol element has break-before the break does not propagate to the
column or the multicol element. And if you have discontiguous elements
collected in a named flow, a break should not propagate to a container
outside of the named flow. Perhaps that's covered by the box/container
terminology, but in that case the break should never propagate to a region
box, either.

Thanks,

Alan