#additional-info

A built-in stream shelf that provides specific information about the input data being parsed in the case of an error. The information provided to #additional-info comes from the markup parser error message. #additional-info can only be accessed from the header and body of sgml-error or markup-error rules.

The information provided is the text of the error message that gives information about this particular error. #recovery-info provides information on how the markup parser will recover from the error and continue processing.

#additional-info is not always attached. Use the is attached test to ensure the stream is attached before attempting to use its value (the information about the input data).

additional-info can also be used as a pattern variable for compatibility with past releases. However, this use is deprecated. Unlike programmer-defined pattern variables, addtional-info must always be heralded with the pattern keyword, even where heralding is usually optional.

When using addtional-info as a pattern variable, use the is specified test to ensure a value has been assigned to the pattern variable.