Truncators, wildcards, and expanders are symbols that can be used replace letters within words. Some of the most common are *, !, and ?.
*
Can be used as a wildcard letter. For instance, lo*n finds both loan and loon.
In Lexis * can be used as a root expander (see ! below), and to fill in any number of letters. For instance, with Lexis, lo*n will find London as well as loan and loon.
!
Can be used as a root expander. For instance impl! finds imply, implication, implied, and implode.
?
In Lexis is a single wildcard letter. Lo?n only finds loan and loon, not London.
Does not work in Westlaw