On 11-8-2009 21:26, Riley, Jenn wrote:
> Hello MODS implementers,
> The MODS/MADS Editorial Committee is in the final stages of
> planning for version 3.4 (very soon now, really!) and one of the
> outstanding issues before us is whether or not to do more with the
> <extension> element. We've heard a number of times along the way
> that it would be helpful to have <extension> not just at the top
> level but also inside specific MODS elements. We'd like to hear
> from you about your current practice and needs for <extension> to
> better plan for how and if this should be implemented.
> 1) What type of data are you currently putting in the top-level
> <extension> element?

The Dutch institutional repositories and the institutional 
repositories that co-operate in the European project NEEO 
( use digital author identifiers (dai) for 
their authors. These identifiers can't be used in the mods:name 
element. Instead we introduce these identifiers in the extension 
element. There is a schema for a daiList. The authors described in the 
name element are linked to the author identifiers in the list in the 
extension element by the ID attribute of the name element and the 
IDref attribute of the corresponding identifier element of the daiList 
in extension.
The two attributes must have the same value to match a name with an 
author identifier.

See for more information: and

> 2) Do you have specific cases in which it would be helpful to you
> to have <extension> inside a specific MODS element rather than at
> the top level to convey additional semantics?

Yes, the digital author identifiers introduced above would have a much 
more natural place within the name element.

> 3) Have you made changes to the MODS schema locally to allow for
> additional elements not in the MODS schema?

No. We think it important not to deviate from the MODS schema. And 
this is not necessary because of the extension element.

For my own institution we use holdingExternal within the location 
element for expressing thresholds of the holdings of print journals in 
a comparable way as SFX does it for electronic journal holdings. 
holdingExternal could be replaced by the extension element when it is 
allowed in all top level elements.

Thomas Place
coordinator SURFshare standards

> Thank you,
> Jenn Riley, on behalf of the MODS/MADS Editorial Committee
> ======================== Jenn Riley Metadata Librarian Digital
> Library Program Indiana University - Bloomington Wells Library W501
>  (812) 856-5759
> Inquiring Librarian blog:

Thomas W. Place ([log in to unmask])
Tilburg University, PO Box 90153, 5000 LE Tilburg, the Netherlands
phone: +31 13 466 2474; fax: +31 13 466 3370