4D v13.4 introduced the ability to modify the AUTO_GENERATE property of a UUID field via code. This also introduced the new MODIFY keyword for specifying which column to modify.

Here is an example of enabling auto_generate for [Table_1]uid:

Begin SQL     ALTER TABLE Table_1 MODIFY uid ENABLE AUTO_GENERATE; End SQL

Here is an example of disabling auto_generate for [Table_1]uid:

Begin SQL     ALTER TABLE Table_1 MODIFY uid DISABLE AUTO_GENERATE; End SQL

Here is the property this is referring to: