[zzo38computer]

I think there is not a problem using multiple kinds of UUIDs in the same system; they will not interfere with each other, because the UUIDs are necessarily different.

Another possibility is to use URIs; UUIDs are URIs too! (Put "urn:uuid:" at front to make a UUID into a URI.)

[rottyguy]

This is an interesting idea. If I want to personalize the urn to my company's uuid, would it be, urn:uuid:mycoid? can it be shorthanded to urn:mycoid?

[zzo38computer]

I do not recommend doing that. Instead, you may wish to either use the plain "urn:uuid:" format, or use a different URI scheme (such as "http") with your company's domain name. A company does not normally have only a single UUID; you can make up additional UUIDs as needed. (If you want to avoid collisions, you can use version 1 UUIDs.)