To this end, the underground has birthed hundreds of ad-hoc Semiotic Unstandard dialects. Many of these are variants of the secret menu pattern, disguising terms as burger toppings.
The Secret Menu
|Pick me up...||You come to me|
|Do you want...||I come to you|
|Let's go to...||Meet at location|
|Eat in||Stay where you are|
|Drive through||Go to ground now|
|Honey mustard||No Danger|
|Barbecue sauce||Low Danger|
|Sriracha sauce||High Danger|
|Cheese||When you can|
|Pickles||Needs done now|
|The Works||We're fucked|
|Ice cream||Occult Stuff|
|Hold the...||Presence unconfirmed|
As you can see, this is a pretty lightweight framework and is very easy to modify or hack for purposes at your own table. (Add it to my old Dungeon Hobo Signs!) Plus you can do fun stuff like sending text messages to your players and they have to use what they know to figure out what's going on.