Preserving entities and language translation

[Warren Block <wblock@wonkity.com>]

Some of the articles in the FreeBSD documentation use entities to 
include large blocks of data.  For example, one article is just a very 
large list of PGP keys for developers: 
https://www.freebsd.org/doc/en_US.ISO8859-1/articles/pgpkeys/index.html

The DocBook article.xml is only 2K, because it does things like this:

  <sect1 xml:id="pgpkeys-officers">
    <title>Officers</title>

    &section.pgpkeys-officers;
  </sect1>

We use xmllint to normalize the article into a single XML file for use 
with PO translation tools.  Of course, all entities are expanded into 
text at that point.

It would be really nice to mark that particular entity as one that 
should be preserved in the translated file.  Is it possible to do that 
with processing instructions or some other method?  For example:

  <sect1 xml:id="pgpkeys-officers">
    <title>Officers</title>

    <?translate off?>
    &section.pgpkeys-officers;
    <?translate on?>
  </sect1>

In the normalized file, it could be a string to indicate to translators 
that it should be left alone:

  <sect1 xml:id="pgpkeys-officers">
    <title>Officers</title>

    <?translate off?>
    do not translate: section.pgpkeys-officers
    <?translate on?>
  </sect1>

Of course, it has to be changed back when the translated XML file is 
generated.

Is there a standard or elegant way to do this?