Hi all,

I'm confused how to correctly mark up page information in MODS. My
issue lies with the "unit" attribute that's supposed to indicate
pages. While the MODS Schema says:

 <xsd:attribute name="unit">
     <xsd:documentation>suggested values: pages, minutes</xsd:documentation>

the online documentation on the MODS web page is ambiguous whether
unit="page" or unit="pages" should be used. This has caused
confusion and interoperability problems between various tools that
support MODS (such as Bibutils, Zotero and refbase).

While <> says
under "18. part/extent":

 Attribute: unit (suggested values: pages, minutes)

the "Detailed Description of MODS Elements"
(.../v3/mods-userguide-elements.html) states under "part/extent":

 unit - Suggested values include page, minute, etc.

and it uses both, unit="page" and unit="pages", in its examples.
The examples linked from the MODS main page all use unit="page".

What is the official recommendation here?

I'd appreciate if the MODS schema and web site would be consistent
with this regard, this would greatly help MODS implementers to
improve interoperability.

Also, on a related issue, I was told that a record which covers only
a single page should be marked up like this:

   <detail type="pages">

i.e. use "part/detail/number" instead of "part/extent" with "start"
and "end" tags having equal page values:

   <extent unit="pages">

However, the MODS Schema contains this note:

 "A single page is indicated by presence of both 'start' and 'end'
  with same value."

What is the correct way of marking up single-page items in MODS?

Adding to the confusing, the MODS online documentation has this

   <detail type="page number">
   <extent unit="pages">

which uses both of the above and uses a different type name. What
type name is recommended for single-page items in MODS, type="page",
type="pages" or type="page number"?

While these sort of issues seem to be minor, the lack of a concise
documentation makes implementation of MODS harder than it should be.

Thanks in advance for any help you can provide.

Best regards, Matthias
Matthias Steffens   ----