Lexmark T620 Technical Reference - Page 272

4-105 PostScript Unsolicited Messages You may receive unsolicited messages from your printer. Unsolicited messages use the same syntax as status messages. These messages are transmitted sequentially as ordinary data through the communication channel, with other characters written to a standard output file. These messages are bracketed with %%[ and ]%%. %%[ Error: error type; Offending Command: operator ]%% The interpreter has detected an error while executing operator and invoked handleerror. %%[ Flushing: rest of job (to EOF) is ignored ]%% The rest of the current print job is discarded because of a previous error or other ending, such as a stop or Ctrl-C. The printer ignores further input until it determines the end of the print job. %%[ exitserver: permanent state may be changed ]%% The PostScript emulation program has exited successfully from the server normal save or restore context; therefore, it can make permanent changes to system parameters or virtual memory.