1. :default CSS pseudo-class

    The `:default` pseudo-class matches checkboxes and radio buttons which are checked by default, `<option>`s with the `selected` attribute, and the default submit button (if any) of a form.

  2. Form attribute

    Attribute for associating input and submit buttons with a form.

  3. Attributes for form submission

    Attributes for form submission that may be specified on submit buttons. The attributes are: `formaction`, `formenctype`, `formmethod`, `formnovalidate`, and `formtarget`

  4. Form validation

    Method of setting required fields and field types without requiring JavaScript. This includes preventing forms from being submitted when appropriate, the `checkValidity()` method as well as support for the `:invalid`, `:valid`, and `:required` CSS pseudo-classes.

  5. formdata api: `formdata()` constructor: `submitter` parameter

  6. gpuqueue api: onsubmittedworkdone

  7. gpuqueue api: submit

  8. htmlformelement api: `requestsubmit()`

  9. htmlformelement api: submit

  10. htmlformelement api: `submit` event

  11. submitevent api

  12. submitevent api: `submitevent()` constructor

  13. submitevent api: submitter

  14. vrdisplay api: submitframe

  15. css selector: `:-moz-submit-invalid`

  16. html element: input: `type="submit"`