These were widely used for at least one thing in practice: adding support for :hover pseudoclass on arbitrary elements (not just <a>) in IE6. https://peterned.h

These were widely used for at least one thing in practice: adding support for :hover pseudoclass on arbitrary elements (not just <a>) in IE6. https://peterned.home.xs4all.nl/csshover.html https://peterned.home.xs4all.nl/csshover.html