Hello everybody, 

Last year we had very much benefits from a good and proper structure on commons, important was that we could tag the pictures with the identifiers.
Currently there are 7 countries/areas which have this structure (see http://commons.wikimedia.org/wiki/Category:Cultural_heritage_monuments_with_known_IDs)
- Andorra
- Flanders (Belgium)
- Estonia
- Netherlands
- Romania
- Spain
- Wallonia (Belgium)

The idea is to set up a similar structure for all participating areas and countries (whenever possible). 
Together with structured tables on the local wiki (with the identifier as a field) this will provide an easy way to add missing pictures. And well it's one of the requirements that pictures have an identifier.

I think it's the best idea when the other countries, which don't have a similar structure yet contact me (I'm away from 4-13 august) or one of the persons who has allready set up a similar structure. You can find me on IRC (name "basvb" if I'm not in the Wikilovesmonumentschannel I'm in #wikipedia-nl), on my commons or preferably my nlwiki talkpage or with an e-mail.