This page provides the following information
GUID : Global Unique Identifier. It is used to identify an object and to ensure its unicity. The object GUID's are generated during the analysis and are saved in the Knowledge base.
If between two versions of analysis, the GUID of an object has changed, the analyzer sees it as a new object and it creates a new object.
The analyzers for which the GUID is calculated are :
IBM PL-PSM z/OS
IBM PL-PSM Universal Database
Oracle Forms / Reports
J2EE Languages and Technologies
Microsoft Visual Basic
You can find the GUID of an object by following the below page once you know the object name.
SQL Queries - CAST Knowledge Base - Queries on objects - How to get object GUID
For a given technology, the GUID formalism is the same for all type of objects.