- [x] [`clip-path`](https://developer.mozilla.org/en/docs/Web/CSS/clip-path): `<clip-source> | [ <basic-shape> || <geometry-box> ] | none` - [x] [`grid-auto-columns`](https://developer.mozilla.org/en/docs/Web/CSS/grid-auto-columns): `<track-size>` - [ ] [`grid-column-end`](https://developer.mozilla.org/en/docs/Web/CSS/grid-column-end): `<grid-line>` - [ ] [`grid-template-columns`](https://developer.mozilla.org/en/docs/Web/CSS/grid-template-columns): `none | <track-list> | <auto-track-list> | subgrid <line-name-list>?` - [x] [`mask-image`](https://developer.mozilla.org/en/docs/Web/CSS/mask-image): `<mask-reference>#` - [ ] [`shape-outside`](https://developer.mozilla.org/en/docs/Web/CSS/shape-outside): `none | <shape-box> || <basic-shape> | <image>` - [ ] [`transition-property`](https://developer.mozilla.org/en/docs/Web/CSS/transition-property): `none | <single-transition-property>#` (MDN has this as `IDENT` which I take to mean using `isCustomIdent`)