In the section 'Required Elements (for Supplemebtary RM Data)'. the Id property is specified as 'Optional but recommended'. This is not consistent with cardinality '1:1'.
Optionality has been reviewed and updated in v0.4 - the id field is mandatory on all resources as it is required for referencing between resources within the FHIR Bundle.
https://github.com/nhsengland/virtual-wards-draft-standards/blob/af2a0cd175e06d48c1084f30abafedad0435722c/FHIR-Resources-Population-Guidance/FHIR-DocumentReference.md?plain=1#L99
In the section 'Required Elements (for Supplemebtary RM Data)'. the Id property is specified as 'Optional but recommended'. This is not consistent with cardinality '1:1'.