Zero or One Occurrences Quantifier (?)

This command is optional.

Indicates that an expression may appear zero or one times. Can be used with or without {Min,Max}. By default, expression quantifiers exhibit greedy behavior. See Expression Quantifiers: Greedy, Reluctant, and Possessive Behavior for more information on changing this behavior.

To use this command:

1. Position the cursor where you want the command inserted.
2. Double-click ? in the Commands list.