This operator may be applied to all machine types. It highlights those states that are nondeterministic, i.e., those states with nondeterministic transitions.
The above diagram shows an example NFA with nondeterministic states q0 and q3. q0 is obviously nondeterministic because of the a transitions. q3 is nondeterministic because JFLAP always considers any state with lambda transitions to be nondeterministic.