Test it on the page above — if you save it, no matter whether you've actually edited something or not, you will receive an empty space instead of {{REVISIONID}}; the only way to recover it is to do a purge.
This might be confusing for some places where {{REVISIONID}} is actually used, especially in combination with parser functions that distinguish preview and saved page this way.
Version: 1.12.x
Severity: normal
URL: http://en.wikipedia.org/wiki/User:Kalan/12694