1. CSS Filter Effects

    Method of applying filter effects using the `filter` property to elements, matching filters available in SVG. Filter functions include blur, brightness, contrast, drop-shadow, grayscale, hue-rotate, invert, opacity, sepia and saturate.

  2. focusin & focusout events

    The `focusin` and `focusout` events fire just before the element gains or loses focus, and they bubble. By contrast, the `focus` and `blur` events fire after the focus has shifted, and don't bubble.

  3. JSON parsing

    Method of converting JavaScript objects to JSON strings and JSON back to objects using JSON.stringify() and JSON.parse()

  4. View Transitions API (single-document)

    Provides a mechanism for easily creating animated transitions between different DOM states, while also updating the DOM contents in a single step. This API is specific to single-document transitions.

  5. DOM Parsing and Serialization

    Various DOM parsing and serializing functions, specifically `DOMParser`, `XMLSerializer`, `innerHTML`, `outerHTML` and `insertAdjacentHTML`.

  6. audiocontext api: `audiocontext()` constructor: `options.sinkid` parameter

  7. audiocontext api: `sinkchange` event

  8. audiocontext api: sinkid

  9. audiosinkinfo api

  10. audiosinkinfo api: type

  11. css api: `supports()` static method: parentheses for single-argument version are optional.

  12. htmlmediaelement api: sinkid

  13. mlgraphbuilder api: sin

  14. processinginstruction api

  15. processinginstruction api: sheet

  16. processinginstruction api: target

  17. xpathresult api: singlenodevalue

  18. css at-rule: `@supports`: `named-feature()`: `named-feature(single-axis-scroll-container)`

  19. css property: appearance: base-select: base styling for single dropdown: `<select>`

  20. types: `<gradient>`: `conic-gradient()`: single color stop and 0-1 positions

  21. types: `<gradient>`: `linear-gradient()`: single color stop and 0-1 positions

  22. types: `<gradient>`: `radial-gradient()`: single color stop and 0-1 positions

  23. types: `<gradient>`: `repeating-conic-gradient()`: single color stop and 0-1 positions

  24. types: `<gradient>`: `repeating-linear-gradient()`: single color stop and 0-1 positions

  25. types: `<gradient>`: `repeating-radial-gradient()`: single color stop and 0-1 positions

  26. types: `<ratio>`: accepts a single <number> as a value.

  27. types: `sin()`

  28. headers http header: if-modified-since

  29. headers http header: if-unmodified-since

  30. headers http header: range: cors-safelisted request header with single `bytes` range

  31. javascript built-in: bigint: asintn

  32. javascript built-in: function: [symbol.hasinstance]

  33. javascript built-in: math: asin

  34. javascript built-in: math: asinh

  35. javascript built-in: math: sin

  36. javascript built-in: math: sinh

  37. javascript built-in: number: isinteger

  38. javascript built-in: regexp: hasindices

  39. javascript built-in: symbol: hasinstance

  40. javascript built-in: temporal api: instant: since

  41. javascript built-in: temporal api: plaindatetime: since

  42. javascript built-in: temporal api: plaindate: since

  43. javascript built-in: temporal api: plaintime: since

  44. javascript built-in: temporal api: plainyearmonth: since

  45. javascript built-in: temporal api: zoneddatetime: since