Once the terms that make up the new glossary entry are added to the term list, the terms must be combined into a Boolean expression. By default, the terms are connected with one another using AND. The options for connecting Glossary terms and defining a pattern are AND, OR and NOT.
AND is the most specific option and requires that all Glossary terms are matched.
OR is less restrictive because the criteria of only one of the Glossary terms must be matched.
NOT allows you to negate the glossary term. For example, you can set up a glossary entry that matches messages that contain HIPAA words but not the word “advertisement.” This glossary entry will not match messages that are advertisements that contain HIPAA words, but will match other messages that contain HIPAA words.
Note: The restriction that terms of
a new Glossary entry can only be either ANDed or ORed with each other
enforces a careful discipline in constructing glossary terms. Each ANDed
or ORed sub-expression in complex Boolean expressions must be named and
made a separate glossary entry. Then using the Existing Entry form, they
can be combined into higher-level glossary entries.
Theoretically, no higher-level glossary needs to be more than two levels
deep. In Boolean algebra this is called disjunctive normal form (i.e.,
the ORing of several ANDed sub-expressions) or conjunctive normal form
(i.e., the ANDing of several ORed sub-expressions). Practically, complex
Boolean expressions may be deeper. However, the discipline of naming each
Boolean sub-expression as a glossary entry helps to ensure both that the
expression will be correct and that the sub-expressions will be easily
available for re-use in other expressions as is often necessary.