When etautil utility is used as a client for IM Provisioning Server, it is required to specify LDAP attribute names, not the display names known from IM User Console or IM Provisioning Manager.
IM documentation does not provide display name -> LDAP attribute name mapping.
Object classes should also be specified by their actual LDAP names in etautil.
For provisioning connectors developed using DYN architecture it's possible to find LDAP names using Connector Xpress.
Similar approach applies to object classes when their LDAP names are needed:
Note: If there's no "Edit Metadata..." in the drop-down menu the Endpoint is not DYN based