Can TagId be considered unique across vCenters

[rdetsch]

Navigation:

1. vSphere
2. Tags and Custom Attributes
3. Tags
4. View TagId of form urn:vmomi:InventoryServiceTag:FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF:GLOBAL

Can this TagId for a user be considered unique for all practice purposes across their vCenters e.g. if a TagId is referenced programmatically or in logs the vCenter host  is not necessary just round robin the vCenters and stop at the first one that has the tag.