### Context MyST-MD has just added support for cross-project xrefs (executablebooks/mystmd#1180) which use a new `xref` scheme, e.g. ```markdown See the spec <xref:spec/some-page#target> ``` See documentation here: https://mystmd.org/guide/external-references We should define this in the spec for other MyST consumers. Some of the thought processes are [here](https://github.com/executablebooks/mystmd/issues/1111).
Context
MyST-MD has just added support for cross-project xrefs (jupyter-book/mystmd#1180) which use a new
xrefscheme, e.g.See documentation here: https://mystmd.org/guide/external-references
We should define this in the spec for other MyST consumers. Some of the thought processes are here.