This sectional specification applies to waveguide type dielectric resonators as custom built products or as standard catalogue items whose quality is assessed on the basis of capability approval. It prescribes the preferred ratings and characteristics with the appropriate tests and measuring methods contained in IEC 61338-1, and gives the general performance requirements to be used in detail specifications for waveguide type dielectric resonators. The concept of preferred values is in general directly applicable to standard catalogue items but does not necessarily apply to custom built products.