Like every software product, 4tH has bugs. Because a work-around is available, fixing these bugs has no high priority.

• When you use '\' without any actual comment in a Unix ASCII file the complete next line will be marked as comment. With MS-DOS ASCII files 4tH will correctly detect a null string and terminate with an error. Use "\ ." just to be safe.
• You cannot comment out '[THEN]' or ')' This is bad practice anyway.