The test group when generating test cases found this conformance unit confusing- the second statement in the CU is not clear:

Descriptor is signed using a digital signature specified in OPC 10000 83 using one of the signing algorithms defined by the UAFX Offline Security Policies. When signing using an RSA algorithm, the PSS padding algorithm should be used whenever possible, e.g. UAFX Offline CertificateSignatureAlgorithm_ RSASAA_PSS-SHA2-256.

the recommendation should say :

When signing using an RSA algorithms, the policies with PSS are recommended over the PKCS policies (i.e. UAFX Offline Security Policy – Rsa-Pss-Sha256 Facet over UAFX Offline Security Policy – Rsa-Pkcs-Sha256 Facet).