Disable/Hide an option set value

We use option sets quite often. Regularly I get asked to change the values of these as business requirements change.

Is there a way to disable an option set value, or hide a value that is no longer available to use?

Eg.

1. Option A
2. Option B
3. Option C

Option B is no longer available. Deleting 'Option B' will delete this value from records already using this value, which I do not want to happen.

A quick fix would be to write 'DO NOT USE - Option B', but this looks messy.

Has anybody got a solution for this.

Thanks in advance.