Note about directionality markup in HTML/XHTML

Hi all (taking i18n core and i18n ITS into the loop),

Andrew Cunningham from the i18n core WG gave some feedback on the BP 
section on directionality (many thanks!). He said that a statement about 
the relation of "its:dir" versus directionality markup in HTML 4.01 (and 
XHTML 1.0) would be helpful. I've tried to come up with something, see 
below. The paragraph could  probably be a note after "Markup is also 
occasionally needed to disable the effects of the bidirectional 
algorithm for a specified range of text." in BP 2.

[[
In HTML 4.01 [1], there is the "dir" attribute with the values "LTR" or 
"RTL", and the "bdo" element  with the values "LTR" or "RTL". The 
semantics of the HTML "dir" attribute values are identical to the 
"its:dir" attribute values "ltr" or "rtl". The semantics of the HTML 
"bdo" element with a "dir" attribute are identical to the "its:dir" 
attribute values "lro" or "rlo". The ITS specification does not propose 
the "bdo" element, since attribute markup is easier to insert into a 
document, and one attribute is sufficient to achieve the same effects as 
the HTML "dir" attribute and the HTML "bdo" element.
]]

[1] http://www.w3.org/TR/1999/REC-html401-19991224/struct/dirlang.html#h-8.2

Looking forward for feedback.

Cheers,

Felix