Documentation is out of date

[Kashkin]

The "Simple Usage" still refers to using classes to tie together selects, rather than data attributes.

Child selects are chained to parent select. All selects must have an id attribute. Child select options must have class names which match option values of parent select. When user selects something in parent select the options in child select are updated. Options which have matching classname with parents currently selected option will stay visible. Others are hidden.