Change a Thread's Subject When the Topic Changes
This is why you should
- change the Subject: header line of a message thread on a mailing list when it becomes apparent that the topic of the thread changes.
To make it clear what has happened (that you are continuing an old thread and not starting a new one), you can include the previous Subject line with the new one.
If the original Subject was "New cloud form discovered!" and you want to change it to "The finest English umbrella" the complete new Subject line could look like "The finest English umbrella (was: New cloud form discovered!)". You can abbreviate the original Subject, of course.
Note: If you reply to a message with a (was:...) block, remove it.

