[NTG-context] \def vs \define

Hi, in this example the question mark nicely becomes part of the command name: \def\OverFull?{\overfullrule30\points} \OverFull? here it does not work at all: \define\OverFull?{\overfullrule30\points} \OverFull? (... but gives "??" instead) As "\define" seems to be more canonical: Does this result mean it is not recommended to use question marks in command names? Steffen