Re: Need for Level Direction Mark

From: Kent Karlsson <>
Date: Mon, 19 Sep 2011 16:09:36 +0200

Den 2011-09-19 04:53, skrev "Peter Edberg" <>:

> Philippe,
> On Sep 17, 2011, at 12:54 PM, Philippe Verdy wrote:
>> Note also that there's no way to specify a weak direction for the
>> internal content of embedded fields, as we don't have the WDE..PDF
>> mechanism described in the UBA for now (but may be we could emulate it
>> using RLE,B..PDF or LRE,B..PDF (but with which B character ?).
> Sorry, which section of the UBA are you referring to that describes WDE (Weak
> Direction Embedding)?

I would guess none, as this was, IIUC, a suggestion for the same thing as:

> Deborah Goldsmith has suggested a "native direction embedding" which is like
> LRE/RLE but uses the inferred primary direction of the embedded text. I will
> try to put together a proposal about this for the next UTC.

And is indeed what I suggested for "(", "[" and other beginning punctuation
(general category Ps and default for Pi) in my response to the PRI,
*without* necessarily actually having a new *control character* for it.
Ending punctuation (Pe and default for Pf) would in my suggestion act like
bidi PDF. Note that the beginning and ending punctuation also must take on
the current (surrounding) embedding directionality, which unfortunately
LRE/RLE/PDF characters by themselves don't do in current UBA; and one must
of course not do rule X9 for characters that aren't pure bidi controls.

>> And I
>> also spoke about interlinear annotations (whose equivalent in HTML is
>> the ruby notation, and in CSS the abolutely positionned blocks with
>> "display:inline-block;position:absolute") which suffer the same
>> problem in the UBA (note that ruby notations are frequently used to
>> insert interlinear translitterations into a different script that may
>> have a different direction than the script used in the annotated
>> text).

I would agree that INTERLINEAR ANNOTATION SEPARATOR should act (for bidi)
as <weak/native directional embedding> (i.e. implicitly have LDM before, and
bidi) like PDF (i.e. implicitly have <PDF, LDM> before and LDM just after
the interlinear annotation terminator).

    /Kent K

>> -- Philippe.
> - Peter E
Received on Mon Sep 19 2011 - 09:16:12 CDT

This archive was generated by hypermail 2.2.0 : Mon Sep 19 2011 - 09:16:14 CDT