'Enchant' was introduced during the rules for 10th edition where in the rules were changed to utilize 'Aura' keywords for enchantments which attach to items.

702.5. Enchant

• 702.5a. Enchant is a static ability, written "Enchant [object or player]." The enchant ability restricts what an Aura spell can target and what an Aura can enchant.
• 702.5b. For more information on Auras, see rule 303, "Enchantments."
• 702.5c. If an Aura has multiple instances of enchant, all of them apply. The Aura's target must follow the restrictions from all the instances of enchant. The Aura can enchant only objects or players that match all of its enchant abilities.
• 702.5d. Auras that can enchant a player can target and be attached to players. Such Auras can't target permanents and can't be attached to permanents.

Translation:

• 702.5a. Enchant is always active. It defines what an aura can attach to.
• 702.5b. Here's somewhere else for you to look for further information.
• 702.5c. If an object has multiple enchants then it must obey all occurrences of enchant.
• 702.5d. If an aura can target players, it cannot target permanents.