Hello,
I notice Reassign tags reassigns tags from white list from a part of a word.
I have the tags asian and caucasian in white list. In galleries i have the custom var caucasian which create tags asian and caucasian.
Also in white list i have the word "69". The "reassign tags" created this tag in all my galleries but i don't have any of those words in most of my galleries ( 69,69er,Position 69 ).