error message when using collect.xref.targets

Hello,

Following the instructions in "DocBook XSL: The Complete Guide",
I am trying to make cross-references from book B to book A using olink.

I went through steps 1 to 4. In step 5, I used the command:

xsltproc --stringparam collect.xref.targets "only" mychunk.xsl bookA.xml

and I obtained the following error (repeated 400 times!)

   Xref is only supported to listitems in an orderedlist:

However, the command ends with:

   Writing target.db for book(bookcA)

My questions:
- What is the meaning of the error message? (I do have 8 ordered
  lists in my book but none with IDs)
  
- Should I worry about these? When I process book B, cross
  references to book A are OK.

Thank you in advance,

Diane

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Diane Larin

Senior Manager - Products and Documentation
INRO
5160 Decarie Boulevard, Suite 610
Montreal (Quebec) Canada  H3X 2H9
Tel: (+1)(514) 369-2023
Fax: (+1)(514) 369-2026
Email: 
Web: http://www.inro.ca/
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