Elaborating on Don Senchuk's comments:
Using OOTB level configurations, the access controls on objects are not governed by revision, but by life cycle states. With this in mind, there is one way you can accomplish this using some slight modification of the concepts in the "Two Phase Development" life cycle template (Life Cycle Template Administrator):
- For life cycle states like In Work, Under Review, Reviewed and Prototype, allow "Set State" action from any of these states to any of these states (assuming you do not want to use promotion objects here) and have all those states using numeric series.
- Designate a specific state (like "Released", for example) to which you can "Set State"/"Promote" from any or all of the numeric revision states.
- For "Released" state, don't allow set state or promotion BACK to the numeric states.
As an example, a brand new created object will be at, say Rev 1. You revise it a few times, set states throughout, etc and end up with an object at Rev 5, in "Reviewed" state. Once you "Set State" or "Promote" to the Released state, it will still be at Rev 5, but then NEXT revision to occur (through manual revision or through change objects) will go to A. There are also ways to conduct the transition between state and numeric->alpha revisions in a single action, instead of having the intermediate "numeric released" object. Once in Released state at Rev A, you now have locked down the LC template to disallow set state
Assuming OOTB revision scheme, once the object hits rev A it will NEVER go back to numeric revisions, even if you were to allow setting state back to the previous "numeric states".
If you have any other questions, feel free to e-mail me at robert.sindelar@eccellent.com, or visit my company's website at www.eccellent.com for more information about what we do.