This question type is a hub, containing code used by several question types and other plugins, developed by POAS department of Volgograd State Technical University:

• backup and restore support for extra_question_fields;
• Unicode string class that allows correct using of [ ];
• base hinting classes for questiontype-specific hints;
• Moodle Forms class for a textarea witht an  icon button on the right;
• PHP libraries for lexical analysis using PHP string as a file.

If you are a developer and interested in using this code in your questions or other plugins, please contact project contributors.