How to condition on a field being blank or empty

A common scenario is to do something if a field is not set or empty.

Add a condition with the following characteristics:

Value	Pattern	Exact	Literal	Negative	Notes

Value	Pattern	Exact	Literal	Negative	Notes
%variable%	\S+	either			\S+ means to look for at least 1 (that is what + means) non-whitespace character Use Negative to reverse the matching on a non-blank character