What’s the difference between an RM (reference material), a CRM (certified reference material) and QCM (quality control material)?

RM (Reference Material) is material, sufficiently homogeneous and stable with respect to one or more specified properties, which has been established to be fit for its intended use in a measurement process.

CRM (Certified Reference Material) is a reference material characterized by a metrologically valid procedure for one or more specified properties, accompanied by a certificate that states the value of the specified property, its associated uncertainty, and a statement of metrological traceability.

QCM (Quality Control Material) is a material intended for internal laboratory quality control. A material or substance one or more of whose property values are sufficiently homogeneous, stable and well established to be used for maintaining or monitoring measurement processes. A QCM does not have formally assigned property values or uncertainties (ISO/CD Guide 80 - Guidance for in-house Production of Reference Materials for Metrological Quality Control (QCMs)).