1. Create page "Bob" Bob Smith.
2. Create page Acme Corporation. Have it reference "Bob" with an alias of "Robert", like "Robert|Bob"
3. Rename page "Bob" to "Bob Smith". Acme Corporation now references "Robert|Bob Smith" as it should.
4. Rename page "Bob Smith" to "Robert Smith". Acme Corporation now references "Robert|Bob Smith|Robert Smith", which is an error.

Acme Corporation
Robert Smith