The "/wdiff" page:
Show the changes to a wiki page.
Query parameters:
- id=HASH
- Hash prefix for the child version to be diffed.
- rid=INTEGER
- RecordID for the child version
- pid=HASH
- Hash prefix for the parent.
The "id" query parameter is required. "pid" is optional. If "pid" is omitted, then the diff is against the first parent of the child.