From Discworld MUD Wiki
A label is an item that can be written on and then stuck to an object or person. Whatever, or whoever, you stuck it to can then be read.
stick label to me You lick the small label and stick it to yourself.
Having a label stuck to yourself gives you a description line:
She has a small label stuck on her.
Having a bath will remove any labels stuck to you.
Removing a label from an item:
remove label from staff You remove one label from the tasselled staff, which breaks into little bits and vanishes.
Darren Spangler's Accessories in the Magical Supplies Emporium sells labels with messages already written on them.