Hi Vicenç. Please consider the concept of "unique identifier"[1]. The only purpose it has is that it must be able to uniquely identify an entity, in this case a momument. A uniquely identified monument can have multiple properties. One of those could be the country it is in (or normalised a country id which is the unique identifier of a country name), or a reference to a unique identifier in a country's system, a municipality's system or an autonomous region's system for monuments.
Unique identifiers are completely trivial and the only requirement is that they are unique and that you do not run out of them before your collection is complete. Unique identifiers are usually optimised for data processing, and databases index integers usually pretty well.
Cheers!
I have some
doubts about the identifiers. How will we distinguish if monument number 50 is
from Nederland or Andorra? Perhaps should it be identified with a prefix (NL-50,
AD-50), or perhaps is there any solution in mind?
Moroever,
in Spain we can find different formats in different sources: "(R.I.) - 51
- 0010580 - 00000", "R-I-51-0010580", and others. Obviously we
need to unify to an unique format and we are discussing it with wm-es, but I
would appreciate some inputs. "R.I." or "R-I" stands for
Registro de Inmuebles (buildings' register) and "51" is the category
for monuments. Probably it is not a good idea to ask participants to type acomplicated number format with spaces, zeros, etc. One solution is to reduce it
to its numeric form "10580" or perhaps to construct a simplified
format like "RI510010580". What are the technical implications about
identifiers, and which would be the best approach?