It's a valid <dashed-ident>.
<rdar://problem/83681811>
We should do this for both @font-palette-values and font-palette. These can be parsing tests.
Created attachment 439803 [details] Patch
This patch modifies the imported WPT tests. Please ensure that any changes on the tests (not coming from a WPT import) are exported to WPT. Please see https://trac.webkit.org/wiki/WPTExportProcess
Created attachment 439928 [details] Patch
Created attachment 440162 [details] Patch for committing
Committed r283539 (242504@main): <https://commits.webkit.org/242504@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 440162 [details].