Your source file can't have the `.ngo' extension.
 Error: Could not open `filename'
 Error: Could not create `filename'
 Error: The disk is full.
 Error: There is a long entry longer than the 17k limit.
 Error: The list of short entries is too long.
 Warning: Can't find the see-also reference `ref'
 Warning: There are too many `:'s in `filename'
 There are too many references to other files.
 Your source file can't use the `.ng' extension.
 You must have a `!name:' field in the control file.
 You need both a title and a file name for menu items.
 You can only have one `!name:' field.
 The `!menu:' field must be before the first file name.
 You need to use a `!menu:' field with more than file name.
 There are too many items in this menu.
 The `!credits:' field must be before any menu or file name.
 There are too many lines in the `!credits:' field.
 Warning, the credit is too long.
 `filename' is not a Norton Guides object file.
 There are too many files in this database.
 Warning: invalid format for !seealso:
 Warning: can't find file for !seealso:
 There is an error in the database file.