Only BookMaster® tags that begin with a colon (:) are highlighted. All tags should be terminated by a period, because ISPF highlights up to the next period. Dot control words (.xx) are never highlighted.

The keyword list supplied by the ISPF comprises the tags used to do logic matching (:xxx/:exxx). Tags that have an optional end tag must have a matching end tag in the edited data for logical highlighting to work. The LOGIC option highlights unmatched end tags (:exxx tags which do not have a corresponding :xxx tag) in reverse video pink.

BookMaster tags are not checked for validity. If you specify a colon (:) as a special character to highlight, the editor does not recognize BookMaster tags.