...record it!
When selecting project in KSW (at startup), check the box "Changed Topic Filename". Then
you can record any number of topic filename changes (and avoid alterations described
above).
Why do I
need to record a change?
Because a topic's KSW identifier is its filename. There are no other stable system file
IDs, not even at the OS file system level.
Note. You only need to record a change if it pertains to an existing topic in project. No need to do it for files that are not currently topics (you actually cannot do it in this case).
Note. If only letter case has changed, recording is automatic. In this case you actually cannot register a change.
See also:
Web Filenames
Unique Filenames
Invalid Filenames