A Trend Micro product comes with a set of predefined expressions. These expressions cannot be modified or deleted.
A Trend Micro product verifies these expressions using pattern matching and mathematical equations. After a Trend Micro product matches potentially sensitive data with an expression, the data may also undergo additional verification checks.
For a complete list of predefined expressions, see http://docs.trendmicro.com/en-us/enterprise/data-protection-reference-documents.aspx.