I prefer [nWF]to n[WF] as other cases might be amiguous. Compare [nWA] vs.
n[WA] does the latter mean that the Alfil portion of the move may not be
a jump? But [nWA] means that the Wzir move must be to an empty square,
while [nWnA] would designate a Wazir move followed by a non-jumping Alfil
move.
I think 'outward' should be implied and we need designators for the
contrary cases, which are less common.