When showing a custom inventory to a player, one has the option to specify a custom title for

that inventory.

Bukkit.createInventory(<holder>, <size>, <custom name>);

However, when trying to apply this concept to the anvil inventory, the name does not change. It stays as the default "Repair & Name". 

Inventory anvilInventory = Bukkit.createInventory(player, InventoryType.ANVIL, "My Custom Title!");
player.openInventory(anvilInventory);