212.4d A local-enchantment spell requires a target whose properties are indicated by the enchantment's subtype. The local-enchantment permanent the spell puts into play can only enchant that type of permanent or player and comes into play attached to the permanent or player the spell targeted. Any additional restrictions on what it can enchant are indicated by phrases like "[This local enchantment] can enchant only a [permanent or player with specified properties]." These restrictions also limit what the local-enchantment spell can target. Similar restrictions can limit what a permanent can be enchanted by. For example, a permanent might have an ability that reads "[This permanent] can't be enchanted by [local enchantments with specified properties]." These restrictions limit whether local-enchantment spells can target the permanent.
Example: An enchant creature spell requires a target creature; an enchant creature in play must enchant a creature.