Minimum was meant as a helper after Patch 9.1 stopped including the minimum player level in the tooltip for items which your character is at, or above, the level required to use the item. The default UI tooltip did, at that time, include a line that warned if the item has a level requirement the player has not yet reached, so this Addon only adds a line if the item is at level, or below. This is primarily a helper for the Auction House, in both the buying and selling of gear. Please feel free to use this code in any Addon for your own purposes, as I lay no claim to ownership or license restrictions.
Note: A subsequent hotfix has restored the minimum player level in the default item tooltip, so this AddOn is no longer necessary. I have decided to keep it available in the event that it is ever needed again.