Toggling this check button in the Spellbook will turn this feature on or off. As such, some spells that should be filtered are not filtered because Blizzard was screwy with the spell name. This feature is limited based on how the spell was named in WoW. Toggling this check button in the Spellbook will switch the spellbook between showing all available spells and highest rank of spells.
This Addon modifies WoW Classic's Spellbook to permit filtering out lower ranks of spells while also having a way to find lower rank of spells when you want to downrank a spell. If you want to take over this project, you may take over the project or continue with your own fork. As such, unless a major necessity is absolutely needed for this addon, I am really not updating this addon.
I did not intend to return for TBC, but I am back.
The Addon still works as intended with no further changes. This update only changes the TOC file to tell WoW that this supports The Burning Crusade.