For example, you'd be surprised at what kinds of email addresses are considered valid according to standards.
Microsoft® Office Front Page® 2003 allows you to create some custom validation within the form feature.
If you need to support these browsers, you must add a polyfill like Ryan Seddon's H5F.
Scroll to and focus the first field with an error upon validation of the form.
The validation rules for standard HTML5 attributes are handled entirely by the browser using the HTML5 Constraint Validation API.
As such, this plugin isn't in control of things like what qualifies as a valid email address or URL.