Lexical Item Text
For obvious reasons a lexical item's main text is the most crucial part of the item. It is the job of the various tests to prompt you for this text in one form or another, but typically you are asked to type it in. If you type it incorrectly then usually the test will mark your answer as incorrect.
But what if you need to insert a comment into the item text that isn't really a part of its usage? You shouldn't have to type it in during a test. Or perhaps different forms of the item text mean the same thing and the test should accept multiple answers? For example, many Spanish verbs have a reflexive form that is interchangeable with its common infinitive form: ejercitar and ejercitarse mean virtually the same thing. Fortunately, both of these situations are accounted for by the program.
Comments can appear anywhere in the item text as long as you enclose them in parentheses. Optional text, on the other hand, is identified with square brackets. In the example above, by entering the item text as ejercitar[se], both ejercitar and ejercitarse will be accepted as correct answers by a definition test.