Source: WowAce

Sorry if this has been asked, but is there a way to ignore statistics for items? For example, for the Ironhoof Destroyer, I have 15 kills from doing it when it was relevant, but I did not get the mount. Now I only have one kill after it became a drop chance and I want to ignore the 15 I did when it was guaranteed. I can't create a custom item because it's the same as an item already in use. And I can't erase the statistic because I can't edit it (grayed out).

and

I guess the ideal situation would be to either have an option to ignore the statistics for an item, or to adjust settings on every item (maybe like an option that says "allow customization" with a warning that you might screw everything up). The idea behind the latter being that I could clear the statistics section of it and it wouldn't pick that up right away.

There are a number of things to consider to avoid this accidentally breaking something, as well as how to design it to make it somewhat intuitive and not utterly confusing (as not all items have statistics tracking in the first place).