• Use the version ID that is generated as the EXTERNALIZATION_VERSION_UID constant. This allows subclasses to use it for their own comparisons.

• If you want to control the EXTERNALIZATION_VERSION_UID, you must model it and specify its initial value in the model. A modeled attribute supersedes the one provided by the code generator.

◦ To calculate this version UID, the code generator uses the name of the parent class, and the names and types of all the non-transient, persistent fields.

◦ It is prudent to manually control this value if the hand-coded externalization is not related to the signature, or footprint, of the non-transient, persistent fields of the class. (This occurrence should be rare.)

• Do not model a serialVersionUIDattribute with a value other than 1 as this disallows the ability to read old versions of the class.