Generic Transparent Exit
"Transparent exits can have extra substitutions in their description and messages; the new substitutions let you put information from the exit's destination into the exit's messages. %c is replaced with a list of the contents of the destination. %w is a list of the players in the destination. %l is the description (looks) of the destination. These substitutions don't conflict with the standard pronoun substitutions; you can still use them in messages. Example: @describe my_exit as \"You see %w standing in the other room.\"."