The bolded part is the placeholder name. This helps you identify the item in game.
The GM Enchant +1 is the number of enchantment levels that the placeholder can increase when redeemed. Most placeholders provide a +1, but others may provide more!
The Max  and Minimum  are the enchantment limits of the placeholder.
The Maximum limit indicates how high the enchantment level on the gear can be after the enchant. In other words, if your item is already at enchantment level , you can't use a number "2" placeholder since its maximum limit is . GM enchantments cannot exceed  if it is level 30 or below, or  if it is level 31 or above. This rule ONLY applies to GM Enchantments. In-game enchantments can go up to  regardless of level.
The Minimum limit indicates how high the enchantment level on the gear must already be when applying the GM enchant. In other words, if your item is only at enchantment level , you cannot use a number "2" placeholder since its minimum limit is . If no minimum limit is specified, then the gear must be enchanted to at least  to apply the placeholder.
Other Enchantment Terminology
No Minimum - This is used on the number "22" and "25" placeholders. This simply means that the item does not need to be enchanted to  to redeem the service. You can use this placeholder to increase the enchant level from .
Auto  - This is used on the number "22" placeholder. It sets the enchantment level on the gear to  regardless of its current enchantment. It does NOT add +5. For example, if your gear was at ,,,, or , this placeholder would change the enchantment to .
Split Enchantments - This is used on the letter "Y" placeholder. Normally you can use the "Y" to add +3 to a piece of gear; however, you can also "split" the bonus between up to three pieces of gear. Note that when using this placeholder a separate ticket must be made with ONLY this placeholder and the gears to be enchanted.