The administrator can define keywords which can be used to tag and categorise bugs. For example, the keyword "regression" is commonly used. A company might have a policy stating all regressions must be fixed by the next release - this keyword can make tracking those bugs much easier.
Keywords are global, rather than per-product. If the administrator changes a keyword currently applied to any bugs, the keyword cache must be rebuilt using the Section 3.15 script. Currently keywords can not be marked obsolete to prevent future usage.
Keywords can be created, edited or deleted by clicking the "Keywords" link in the footer. There are two fields for each keyword - the keyword itself and a brief description. Once created, keywords can be selected and applied to individual bugs in that bug's "Details" section.