1. Printing Events

    Window fires `beforeprint` and `afterprint` events so the printed document can be annotated.

  2. CSS Generated content for pseudo-elements

    Method of displaying text or images before or after the given element's contents using the ::before and ::after pseudo-elements. All browsers with support also support the `attr()` notation in the `content` property.

  3. CSS page-break properties

    Properties to control the way elements are broken across (printed) pages.

  4. DOM manipulation convenience methods

    jQuery-like methods on DOM nodes to insert nodes around or within a node, or to replace one node with another. These methods accept any number of DOM nodes or HTML strings as arguments. Includes: `ChildNode.before`, `ChildNode.after`, `ChildNode.replaceWith`, `ParentNode.prepend`, and `ParentNode.append`.

  5. beforeinstallpromptevent api

  6. beforeinstallpromptevent api: `beforeinstallpromptevent()` constructor

  7. beforeinstallpromptevent api: platforms

  8. beforeinstallpromptevent api: prompt

  9. beforeinstallpromptevent api: userchoice

  10. beforeunloadevent api

  11. beforeunloadevent api: returnvalue

  12. beforeunloadevent api: user interaction required for dialog box

  13. characterdata api: before

  14. documenttype api: before

  15. document api: `beforescriptexecute` event

  16. element api: before

  17. element api: `beforematch` event

  18. element api: `beforescriptexecute` event

  19. element api: `beforexrselect` event

  20. htmlelement api: `beforeinput` event

  21. htmlelement api: `beforematch` event

  22. htmlselectelement api: add: index as `before` parameter

  23. nodeiterator api: pointerbeforereferencenode

  24. node api: insertbefore

  25. range api: setendbefore

  26. range api: setstartbefore

  27. svglengthlist api: insertitembefore

  28. svgnumberlist api: insertitembefore

  29. svgpointlist api: insertitembefore

  30. svgstringlist api: insertitembefore

  31. svgtransformlist api: insertitembefore

  32. window api: `beforeinstallprompt` event

  33. window api: `beforeprint` event

  34. window api: `beforeunload` event

  35. window api: `beforeunload` event: activation using `event.returnvalue = "string";`

  36. window api: `beforeunload` event: activation using `event.preventdefault()`

  37. window api: `beforeunload` event: activation using `return "string";`

  38. css property: -webkit-border-before

  39. css property: break-before

  40. css property: break-before: supported in multi-column layout

  41. css property: break-before: supported in multi-column layout: `always`

  42. css property: break-before: supported in multi-column layout: `avoid`

  43. css property: break-before: supported in multi-column layout: `avoid-column`

  44. css property: break-before: supported in multi-column layout: `column`

  45. css property: break-before: supported in paged media

  46. css property: break-before: supported in paged media: `always`

  47. css property: break-before: supported in paged media: `page` and `avoid-page`

  48. css property: break-before: supported in paged media: `recto` and `verso`

  49. css property: page-break-before

  50. css selector: `::before`: animation and transition support