iTerm2 supports several non-standard escape codes. These may not work properly in tmux or screen, and may have unknown effects on other terminal emulators. Proceed with caution. The control sequences use the following notation: ESC means "Escape" (hex code 0x1b) . ST means either BEL (hex code 0x07) or ESC \\. Spaces in control sequences are to be ignored. Values in [brackets] are variable paramet