Writing and hanging a label in Anytag

The text on the label is simply the item's name, so you set it the same way you name anything else: rename the Anytag on an anvil to whatever the label should say.

Then right-click the block you want to mark. The item is consumed and the text appears in the air just in front of that block. It stays exactly where you put it - it does not drift, does not need a surface behind it, and takes up no block space, so it works over a chest, beside a gate, above a crop bed or halfway up a post.