[jats-list] BITS index terms

["Imsieke, Gerrit, le-tex" <gerrit.imsieke@xxxxxxxxx>]

What is the canonical way to model a two-level index term? Apparently 
BITS permits these two variants:

1)
<index-term>
  <term>primary</term>
  <index-term>
    <term>secondary</term>
  </index-term>
</index-term>

2)
<index-term>
  <term>primary<index-term>
      <term>secondary</term>
    </index-term></term>
</index-term>

On 
http://jats.nlm.nih.gov/extensions/bits/tag-library/0.2/index.html?elem=index-term, 
both variants seem legit.

But I haven't understood why index-term elements should be permitted in 
the mixed-content model of term. This also permits b in my view b 
non-sensical constructs such as this:

<index-term>
  <term>primary<index-term>
      <term>secondary</term>
    </index-term> and <index-term>
      <term>another embedded</term>
    </index-term></term>
</index-term>

There are two embedded index-terms in the primary term. How should an 
index entry that is generated from this look like?

primary
 - another embedded
 - secondary

So should it actually create two secondary terms for the primary? But 
there we wilfully dropped the phrase " and " between the two index 
terms. This has to be included somehow.

So is the expected rendering like this?

primary and
 - another embedded
 - secondary

This seems highly non-sensical.

So shouldn't we rule out index-terms within terms and only permit the 
first variant where the subordinate index-term comes after the term?

The root cause of this issue seems to be that the term content model has 
been designed for terms in definition lists. However, the content model 
of terms within index-terms should exclude index-terms. If you want to 
model this with DTDs, you'll have to rename one of the terms, or impose 
additional constraints that could be checked with Schematron.

Thoughts? Do you agree that the variant-2-approach should be deprecated?

Gerrit


--
Gerrit Imsieke
GeschC$ftsfC<hrer / Managing Director
le-tex publishing services GmbH
Weissenfelser Str. 84, 04229 Leipzig, Germany
Phone +49 341 355356 110, Fax +49 341 355356 510
gerrit.imsieke@xxxxxxxxx, http://www.le-tex.de

Registergericht / Commercial Register: Amtsgericht Leipzig
Registernummer / Registration Number: HRB 24930

GeschC$ftsfC<hrer: Gerrit Imsieke, Svea Jelonek,
Thomas Schmidt, Dr. Reinhard VC6ckler