Warning: hidden \ in filename format string tag placeholders

Anyone using format string tag placeholders in Tag-Filename or Export "Export file name" might like to know of this hazard. If you use a string

$validate(%band% ~ %album%.htm,_)

(as I do to create an album info file in each album directory) and one of those tags values contains a \ character (unlikely but can happen), then that \ gets interpreted as a pathname element separator, creating a folder where one did not intend one. The fix is e.g.

$replace($validate(%band% ~ %album%.htm,),,)