1. console api: `dirxml()` static method

2. mouseevent api: layerx

3. svgellipseelement api: rx

4. svgfeconvolvematrixelement api: orderx

5. svgrectelement api: rx

6. vttregion api: regionanchorx

7. vttregion api: viewportanchorx

8. css property: rx

9. css property: rx: auto

10. svg element: ellipse: rx

11. svg element: rect: rx