[Al Skierkiewicz]

R69 seems to be the definitive command although it is referenced by other rules. My boldface added...

<R69> Reaction of the ROBOT to communications received from the SIGNALING DEVICE must
meet all of the following criteria:
 For a single MATCH, the ROBOT shall be limited to react to a maximum of four distinct
commands - either through hardware or software limitations, or a combination of the two.
 The ROBOT shall not dynamically change the recognized command set during a MATCH.
 The ROBOT may only seek out and react to permitted SIGNALING DEVICES belonging to
the assigned ALLIANCE (as defined in Rule <R65>). Intentionally reacting to other
SIGNALING DEVICES is prohibited.

See also R65 for specifics on the interaction with THE robocoach and size limitations. Additionally, R65 implies that the you are not limited to using the IR board.
<R65> SIGNALING DEVICES shall be designed to communicate signals from the ROBOCOACH
to the ROBOT. SIGNALING DEVICES are excluded from Rule <R64>. SIGNALING
DEVICES shall:
use either passive (no emission of any electromagnetic radiation) or active (emits some
restricted form of electromagnetic radiation) means of communication