Description
The documentation for swhid is below:
Asserts the identity of the component using the Software Heritage persistent identifier (SWHID). The SWHID, if specified, MUST be valid and conform to the specification defined at: https://docs.softwareheritage.org/devel/swh-model/persistent-identifiers.html.
Many SWHID especially based on content and directory type are not unique and hence requires additional qualifiers such as anchors.
Below is a snippet from the swhid docs
This means, for example, that you should prefer swh:1:dir:a8eded6a2d062c998ba2dcc3dcb0ce68a4e15a58;anchor=swh:1:rel:22ece559cc7cc2364edc5e5593d63ae8bd229f9f over swh:1:rel:22ece559cc7cc2364edc5e5593d63ae8bd229f9f.
Similar to purl, I think the swhid attribute in the specification must allow qualifiers. This could be clarified via the documentation.