What do the abbreviations L, NG, OT and Z on the lid of a cardboard drinking beaker mean? [closed]
The knobs are so that the servers can depress them, and keep track of what is in the cup.
For example, on the web, I can find a picture of a lid which has knobs labeled diet, tea, cola, other. When a server fills a cup with tea, they depress the knob labeled "tea" on the lid so as to make sure the customer gets the correct cup.
I have no idea what L, NG, OT, and Z are, though. They don't really sound like English abbreviations for various drinks.