IntelliSpell uses two wildcard characters: ? and *. The ? is to represent any single character, while the * represents zero or more of any character. So for example, if you add th* to your wildcard list, any word beginning with a lowercase "th" will be ignored by IntelliSpell. If you added th? to the wildcard list, then any three letter word beginning with a lowercase th will be ignored by IntelliSpell; however, in this situation, a four letter word beginning with th will be checked by IntelliSpell. Also, please note that the wildcard syntax is case sensitive.