Confirming "remove from history"

In Convert/Tag-Filename, the a pull-down menu of past formats gets cluttered. To remove no-longer-used formats, I choose one and then click the right arrow and select "Remove from History."

However, I learned the hard way that this removal is only temporary unless I eventually select a format and click OK to perform the rename. If I just close the dialog without selecting a format, then the removal is undone and the unwanted format returns the next time I invoke Convert/Tag-Filename.

 - Rich