1. EventTarget.addEventListener()

    The modern standard API for adding DOM event handlers. Introduced in the DOM Level 2 Events spec. Also implies support for `removeEventListener`, the [capture phase](https://dom.spec.whatwg.org/#dom-event-capturing_phase) of DOM event dispatch, as well as the `stopPropagation()` and `preventDefault()` event methods.

  2. selector list argument of :not()

    Selectors Level 3 only allowed `:not()` pseudo-class to accept a single simple selector, which the element must not match any of. Thus, `:not(a, .b, [c])` or `:not(a.b[c])` did not work. Selectors Level 4 allows `:not()` to accept a list of selectors. Thus, `:not(a):not(.b):not([c])` can instead be written as `:not(a, .b, [c])` and `:not(a.b[c])` works as intended.

  3. selector list argument of :nth-child and :nth-last-child CSS pseudo-classes

    The newest versions of `:nth-child()` and `:nth-last-child()` accept an optional `of S` clause which filters the children to only those which match the selector list `S`. For example, `:nth-child(1 of .foo)` selects the first child among the children that have the `foo` class (ignoring any non-`foo` children which precede that child). Similar to `:nth-of-type`, but for arbitrary selectors instead of only type selectors.

  4. Datalist element

    Method of setting a list of options for a user to select in a text field, while leaving the ability to enter a custom value.

  5. Reversed attribute of ordered lists

    This attribute makes an ordered list number its items in descending order (large to small), instead of ascending order (small to large; the default). The order that the list items are displayed in is not affected.

  6. "once" event listener option

    Causes an event listener to be automatically removed after it gets invoked, so that it only gets invoked once. Similar to jQuery's `$.one()` feature.

  7. Passive event listeners

    Event listeners created with the `passive: true` option cannot cancel (`preventDefault()`) the events they receive. Primarily intended to be used with touch events and `wheel` events. Since they cannot prevent scrolls, passive event listeners allow the browser to perform optimizations that result in smoother scrolling.

  8. counter api: liststyle

  9. css property: list-style

  10. css property: list-style-image

  11. css property: list-style-image: none

  12. css property: list-style-position

  13. css property: list-style-type

  14. css property: list-style-type: afar

  15. css property: list-style-type: amharic

  16. css property: list-style-type: bengali

  17. css property: list-style-type: binary

  18. css property: list-style-type: circle

  19. css property: list-style-type: decimal

  20. css property: list-style-type: disc

  21. css property: list-style-type: hangul

  22. css property: list-style-type: hebrew

  23. css property: list-style-type: kannada

  24. css property: list-style-type: khmer

  25. css property: list-style-type: lao

  26. css property: list-style-type: none

  27. css property: list-style-type: octal

  28. css property: list-style-type: oriya

  29. css property: list-style-type: oromo

  30. css property: list-style-type: sidama

  31. css property: list-style-type: somali

  32. css property: list-style-type: square

  33. css property: list-style-type: tamil

  34. css property: list-style-type: telugu

  35. css property: list-style-type: thai

  36. css property: list-style-type: tigre

  37. css property: list-style-type: urdu

  38. css property: list-style: inside

  39. css property: list-style: none

  40. css property: list-style: outside

  41. css property: list-style: `symbols()`

  42. css selector: selector list (`,`)

  43. javascript built-in: intl: listformat: format

  44. javascript built-in: intl: listformat: formattoparts

  45. javascript built-in: intl: listformat: `listformat()` constructor

  46. javascript built-in: intl: listformat: resolvedoptions

  47. javascript built-in: intl: listformat: supportedlocalesof