how to add a non-single valued attribute, like memberOf

[Alan Buxey]

depends whats being carried in the memberOf field and its purpose. if
you want to use it with a wider selection of SPs in federated manner
you'll probably be better off using something in the eduPerson scope
eg https://www.internet2.edu/products-services/trust-identity/mace-registries/internet2-object-identifier-oid-registrations/
, in which case, check if what you're passing out is suitable for eg
eduPersonEntitlement,
eduPersonAffiliation or even eduPersonOrgUnitDN -  using one of these
values should enable easier SP integration.

alan.