The following image illustrates that the second revision (B) in the plant was revised into a sub configuration, as revision (C), which was signed off and now has been subsequently revised to revision (D) within the project.
The new revision (D) in the lower configuration is initially in a working state and has a modified icon to indicate that it is both working and the result of a revise to a lower configuration and retains the higher configuration design basis, from where it originated. When the lower configuration revision (D) is signed off, it is given an icon indicating that it is both current and the result of a revise in a lower configuration.
If the current revision (D) is revised again at the lower configuration, the next revision retains the higher configuration design basis, from which it originated. The new working revision icon is the same as the first working revision at the lower configuration and the result of a downwards configuration revision.