impliedAclModes

The full set of WAC acl:mode predicates a grant of this mode must write. WAC has no mode subsumption — acl:Write does not grant acl:Read — so a UI capability that's meant to include reading has to assert acl:Read explicitly:

• READ → acl:Read ("View")

• APPEND → acl:Read, acl:Append ("Add": read + append)

• WRITE → acl:Read, acl:Write ("Edit": read + modify)

Without the explicit acl:Read a "Write" receiver could overwrite a resource they cannot GET.