Upgrade scripts 4.x > 5.x seems have some inconsistence - or my misunderstandings???

[Eduard Tibet <eduard.tibet@gmail.com>]

Hi!

I had some task to upgrade old 4.5 DocBook format files into the fresh
new 5.1 by using well known "How to" located at [1] and upgrade script
[2]. But while digging deeper and deeper into scripts I began to find
some inconsistence regarding upgrade process and other stuff.

If I need to file a bug at GitHub let me know. But I decided to write
it here first because maybe that is my primary misunderstanding on
certain details rather than actual bugs in files.

1. DocBook 5.1 is now an OASIS standard, but the script [2] put the
version 5.0 (not 5.1) in document header while using:

<xsl:param name="db5.version" select="'5.0'"/>

despite the url in script location string quite clear show us the
right version - 5.1

Of course, I can change the param value by myself BUT is it a bug or
5.0 within 5.1 script is specially left there for some purposes?

2. By default update script doesn't include xml declaration <?xml
version="1.0" encoding="utf-8"?> by applying
omit-xml-declaration="yes" statement. Despite this the "Example 2" in
[3] clearly shows xml declaration. Are there any reasons to NOT
include xml declaration in converted document using default script?
Once again, I can change these values by myself but I need to
understand the reasons it was done such way by default.

3. While digging into the schema set file [4] the linking to 5.1CR4
despite it belongs to 5.1
BTW, there is a comment there:

"This is the source format for the catalog; replace 5.1CR4 with the
appropriate versions before publishing it! "

But I don't know about whom that comment is related to - people
publishing it on the web (i.e. TC members) or users of DocBook
standard?

Thanks!

--
regards,
 ET

[1] http://docbook.org/docs/howto/howto.html
[2] http://cdn.docbook.org/schema/5.1/tools/db4-upgrade.xsl
[3] http://docbook.org/docs/howto/howto.html#introduction-rng
[4] http://cdn.docbook.org/schema/5.1/catalog.xml