I KNOW this has been reported before, but I haven't seen it specifically in regards to tile entities such as Dispensers and Command Blocks that store their name in their NBT data.

Rename a Dispenser or any other tile entity in an anvil. Place the block and remove it from your entity. Control/Command-Pick the block, and you will receive a Dispenser named Dispenser with (+NBT) description, when the only NBT data is the altered name. In this particular case, it SHOULD show the correct name when you mouse over it in your inventory (If you place and open it, it will show the correct name). Up to devs whether it shows +NBT in this case or not, that's not the issue.