The section on unforced breaks currently has the text:

If even that does not lead to sufficient break points, cloned margins/border/padding at the block-end side are truncated; and if more room is still needed, cloned margins/border/padding are truncated at the block-end side as well.

The "if more room is needed" clause is saying the same thing as the previous clause, which doesn't make sense.

I suspect it probably intended to say block-start rather than block-end side for the "if more room is needed" behavior at the end of the sentence.