Dear Teresa,


at Rostock University Library we use Persistent URLs in CONTENTIDS.
In one of our digitization projects we also decided to use UUIDs as object ids.
Since we host our own PURL-Resolver, we could simply append the UUIDs to a URL. For elements of the internal structure we combine the UUID of the object with the ID of the DIV element.


One example METS can be found here:


In your case your right. You cannot put the UUID into the ID-attribute. On a conceptual level nobody can forbid the use of  UUID for IDs. If they are gloabally unique they are also unique within the XML document. But technically UUIDs do not comply with the XML-ID-Type (e.g. IDs cannot start with a number and cannot contain „:“) (


In your case I see several possibilities to convert the UUID-string into a URI:


a)  Output them as URN (wich is a valid URI) by using the prefix: „urn:uuid:“:
The URN-UUID-scheme is definied in

e.g.:   urn:uuid:f81d4fae-7dec-11d0-a765-00a0c91e6bf6

b)      Define a local URL-Prefix like
If you do so, you can „claim“ the UUIDs as definied by your institution and later you could decide to implement your own resolver which leeds to the presentation of the object in your digital library.

c)       Alternatively you can define metadata sections (mets:dmdSec) for each div and link them via dmdid attribute.
Within this metdata section you can use MODS or another metadata schema to store the UUID.


Kind regards,


Robert Stephan




Dipl.-Inf. Robert Stephan

- Digitale Bibliothek -


Universitätsbibliothek Rostock

18051 Rostock

Tel.: +49 (381) 498 8625


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Von: Metadata Encoding and Transmission Standard <[log in to unmask]> Im Auftrag von Teresa Soleau
Gesendet: Samstag, 23. März 2019 00:38
An: [log in to unmask]
Betreff: [METS] CONTENTIDS example; where are you putting unique external IDs?




We are trying to find a place in the METS structMap divs to put UUIDs referring to unique physical objects that have been digitized (like a barcode for the physical object) and CONTENTIDS seems like a good element to use (since the ID element is only supposed to refer to links internal to the METS, right?) but I’d like to see an example of the CONTENTIDS values. The type is URI, not string.


Anyone adding this type of information to your METS documents and could share where you’ve added it?



~Teresa Soleau



Digital Preservation & Library Systems Manager

Collection & Content Management Systems

J. Paul Getty Trust
1200 Getty Center Drive
Los Angeles, CA 90049-1688
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