1. :optional CSS pseudo-class

    The `:optional` pseudo-class matches form inputs (`<input>`, `<textarea>`, `<select>`) which are not `:required`.

  2. ::placeholder CSS pseudo-element

    The ::placeholder pseudo-element represents placeholder text in an input field: text that represents the input and provides a hint to the user on how to fill out the form. For example, a date-input field might have the placeholder text `YYYY-MM-DD` to clarify that numeric dates are to be entered in year-month-day order.

  3. Form attribute

    Attribute for associating input and submit buttons with a form.

  4. Color input type

    Form field allowing the user to select a color.

  5. Date and time input types

    Form field widgets to easily allow users to enter a date, time or both, generally by using a calendar/time input widget. Refers to supporting the following input types: `date`, `time`, `datetime-local`, `month` & `week`.

  6. Email, telephone & URL input types

    Text input fields intended for email addresses, telephone numbers or URLs. Particularly useful in combination with [form validation](https://caniuse.com/#feat=form-validation)

  7. input event

    The `input` event is fired when the user changes the value of an `<input>` element, `<select>` element, or `<textarea>` element. By contrast, the "change" event usually only fires after the form control has lost focus.

  8. inputmode attribute

    The `inputmode` attribute specifies what kind of input mechanism would be most helpful for users entering content into the form control.

  9. Number input type

    Form field type for numbers.

  10. input placeholder attribute

    Method of setting placeholder text for text-like input fields, to suggest the expected inserted information.

  11. Range input type

    Form field type that allows the user to select a value using a slider widget.

  12. Search input type

    Search field form input type. Intended to look like the underlying platform's native search field widget (if there is one). Other than its appearance, it's the same as an `<input type="text">`.

  13. MediaRecorder API

    The MediaRecorder API (MediaStream Recording) aims to provide a really simple mechanism by which developers can record media streams from the user's input devices and instantly use them in web apps, rather than having to perform manual encoding operations on raw PCM data, etc.

  14. readonly attribute of input and textarea elements

    Makes the form control non-editable. Unlike the `disabled` attribute, `readonly` form controls are still included in form submissions and the user can still select (but not edit) their value text.

  15. htmlinputelement api: form

  16. htmlinputelement api: formaction

  17. htmlinputelement api: formenctype

  18. htmlinputelement api: formmethod

  19. htmlinputelement api: formnovalidate

  20. htmlinputelement api: formtarget

  21. html element: input: form

  22. html element: input: formaction

  23. html element: input: formenctype

  24. html element: input: formmethod

  25. html element: input: formnovalidate

  26. html element: input: formtarget