You can give the user rights to certifications by giving him rights to all certifications, and/or giving him rights to the individual certification types, with the user getting the sum of the two. For example, giving him "View" to all certifications and "Create" to "Background results" lets him view any certification type and create new "Background results" certifications. The user can only perform actions for which he has rights with one exception: if he has "Edit" rights, he can also view the certification.