Is it a bad practice to add extra attributes to HTML elements?

Question

Sometimes I add an attribute to some of my controls. Like:

Chris Sharma

I know it

Answer 1

Using jquery,

to store: $('#element_id').data('extra_tag', 'extra_info');

to retrieve: $('#element_id').data('extra_tag');

This was also posted @ [http://stackoverflow.com/a/16985773/2458978][1]

[1]: How to store arbitrary data for some HTML tags