Install sgmls-doc by entering the following commands in the terminal:
sudo apt update sudo apt install sgmls-doc
Description:
HTML documentation of libsgmls-perl and sgmlspl
libsgmls-perl and sgmlspl are tools for parsing the output from an SGML parser . This package contains the documentation in HTML format of the packages libsgmls-perl and sgmlspl.
Homepage: http://search.cpan.org/dist/SGMLSpm/
Version: 1.03ii-36
Section: universe/doc