The International Vocabulary of Metrology (VIM 2.44) defines a verification as provision of objective evidence that a given item fulfils specified requirements. EXAMPLE 1. Confirmation that a given reference material as claimed is homogeneous for the quantity value and measurement procedure concerned, down to a measurement portion having a mass of 10 mg. EXAMPLE 2. Confirmation that performance properties or legal requirements of a measuring system are achieved. EXAMPLE 3. Confirmation that a target measurement uncertainty can be met. NOTE 1. When applicable, measurement uncertainty should be taken into consideration. NOTE 2. The item may be, e.g. a process, measurement procedure, procedure, material, compound, or measuring system. NOTE 3. The specified requirements may be, e.g. that a manufacturer's specifications are met. NOTE 4. Verification in legal metrology, as defined in VIML, and in conformity assessment in general, pertains to the examination and marking and/or issuing of a verification certificate for a measuring system. NOTE 5. Verification should not be confused with calibration. Not every verification is a validation. NOTE6. Inchemistry, verification of the identity of the entity involved, or of activity, requires a description of the structure or properties of that entity or activity.