Matt Jones wrote:

The term GUID is one we started using in SEEK when looking for a solution to the identity and resolution problems that we saw looming for the Taxonomic COncept Standard. Dave Thau's presentation on this (linked on the GUID wiki) defines this pretty well and explores the issues.

Here we see a tipical trouble with identifier and identity. Do you mean identity of an object (a unique thing, so we don't need identifier because it is the thing) or equivalence of data (there can be multiple data objects having the same value)? Where we need GUID we can't rely on identity, in my understanding.

"globally unique" means simply that an identifier that is issued can only have one valid interpretation across all possible systems.

What do you mean by valid? Suppose a data object in data provider's database. A GBIF portal has its copy when last a user accessed to the data object. The data provider changes its contents for some reason afther the last access through the GBIF portal. What is the valid interpretation of these data objects? Tha provider's one?

Regardless of the mechanism used to resolve the identifier, the object that the id 'identifies' will be bit-for-bit identical.

So you mean equivalence, not identity. If it is bit-for-bit equivalence, why do you need GUID? The contents IS the GUID you defined.

There are some tricky issues dealing with granularity of the identifier for digital data (does the identifier point at a tuple in an entity, or at a whole entity, or at multiple entities).

Do you mean your bit-for-bit GUID requires scope disamibugater also? Isn't it assigned to a data object, i.e. unit to be handled as a chunk?

It may be better to use other words such as globally disambiguateor or distinguisher, because we do not mean identity by identifier.

Cheers, James