Minecraft wiki entry for Before_1.8, associated text: Renaming any item, including normal blocks. Besides entertainment value, this can save on the costs of repeated repairs. Blocks lose the rename when placed
Repairing a "tiered" item with units of its material. (For example, iron ingots can be used to repair iron tools and armor.) Acceptable items for repair have the material to use in their default name, except for chainmail, which is repaired with iron ingots.
Combining two items of the same kind that have durability. (For example, bows, shears, etc.) The durabilities will combine similar to using a crafting table, and the enchantments are combined following rules detailed below.
Combining a tool with an enchanted book to add the book's enchantment to the tool. This costs much less than combining two similar items, and can give enchantments to items that they could not get at an enchanting table.
Crushing any players who happen to walk under or be under the anvil while it is falling.