Changes in Existing Form Controls and Attribute

HTML5 provides a number of ways to validate form fields; certain input types such as email and url, for example, as well as the required and pattern attributes. If want to use these input types without native validation of its fields and allow the form to be submitted, use the new Boolean novalidate attribute.

The forms no longer need to have the action attribute defined. If omitted, the form will behave as though the action were set to the current page.

The autocomplete attribute can also be added directly to the form element; in this case, it will apply to all fields in that form unless those fields override it with their own autocomplete attribute.

In HTML5, you can have an optgroup as a child of another optgroup, which is useful for multilevel select menus.

Unlike HTML 4, in HTML5, the rows and cols attributes are no longer required to specify a textarea element’s size. You should use CSS to define a textarea’s width and height.

HTML5 wrap attribute applies to the textarea element, and can have the values soft (the default) or hard. With soft, the text is submitted without line breaks other than those actually entered by the user, whereas hard will submit any line breaks introduced by the browser due to the size of the field. If you set the wrap to hard, you need to specify a cols attribute.