thongage

Etymology

 * restaurant sense modelled on, coined by Darwin restaurant owner John Spellman.

Noun

 * 1) Part of a thong (underwear) visible when worn.
 * 2)  A restaurant surcharge added to the bill for patrons who wear thongs (footwear) instead of shoes.

Usage notes
The restaurant surcharge was actually only ever applied in Spellman's Darwin restaurant, but the word and practice received a great deal of media attention.