Comment on WD 14496-22

[mpsuzuki at hiroshima-u.ac.jp]

Dear Sirs,

I appreciate your efforts to update ISO/IEC 14496-22
for synchronization to OpenType 1.5. One of the interesting
feature of OpenType 1.5 for CJKV people is the explicit
support of Unicode Variation Sequences.

Yet I've not checked in full, but now I have 3 questions
on ISO/IEC 14496-22 2nd ed. WD.

ISO/IEC 10646 and Unicode references
------------------------------------

After ISO/IEC 10646:2003, there are 2 amendments,
Amd.1:2005 and Amd.2:2006. Unicode 5.0 claims it
supports these 2 amendments, so, I think there's no 
reason to exclude these amendments from the normative
list, except an editorial reason to avoid "too many
references".

Speaking as a person from Japan, Amd.1:2005 includes
the update for Japanese industrial standard of
character set JIS X 0213:2004, so I wish if ISO/IEC
10646 amendments are explicitly cited.

One of the remarkable feature of OpenType 1.5 is
variation sequence support by cmap format 14.
Unicode variation sequence is a part of Unicode,
but there is more "normalized" operation of UVS,
Ideographic Variation Database (IVD)
	http://www.unicode.org/ivd/index.html
IVD is standardized by Unicode Technical Standard #37,
	http://www.unicode.org/reports/tr37/
but this is NOT a part of Unicode standard. So, I'm
interested in if ISO/IEC 14496-22 will list it in
Normative Reference, or not, or leave it to OpenType
specification maintainers.


version number
--------------
In the case of Open Font Format, there is an idea of version
number (except of the publishing date of ISO/IEC 14496-22)?
If there is, ISO/IEC 14496-22:2007 is 1.0? Or, to synchronize
with OpenType v1.4, it should be 1.4? There might be 2 different
ways of correction, I think.

correction a)
remove the sentence. Because OpenType 1.3 was never standardized
as a part of ISO, so it's reasonable to claim that there's no
previous version of OFF before ISO/IEC 14496-22:2007.

correction b)
replace it as "OpenType 1.3" as original OpenType 1.4 spec said.

OpenType layout feature registry
--------------------------------

On 14496-22 2nd WD p. 296-300 "5.4.3.1 Feature Tag List",
there are 2 undescribed tags.

In OpenType 1.4 & 1.5, "jp04" and "hojo" tags are listed
and described. In ISO/IEC 14496-22:2007, they are not
listed and not described. In 14496-22 2nd ed WD, they
are listed but not described. Personally, I wish if they
are listed and described, but if there's background
reason to drop them in ISO/IEC 14496-22:2007 (and it's not
outdated), they should be dropped in the 2nd edition either.

Regards,
mpsuzuki