This is an EAL expression available on Guid Type attributes to create a new Guid object and store it in the Guid attribute.

NOTE: Guid attribute should not be null to use this expression.

Example

self.Guid.newGuid

or

self.Guid:=Guid.NewGuid

Example 2

Using SysUser package as an example.

SysUser.allInstances->first.Guid.newGuid

This will create a new Guid for the first record.