There has been significant expansion and development in clinical laboratory sciences with many international groups providing recommendation for changes. This book groups and updates the recommendations and will be appropriate for laboratory scientists, medical professionals and students in this area.

History of recommendations on properties and units in clinical laboratory sciences; Definitions of some disciplines applied in the clinical laboratory; Conventions and instructions for use; Fundamental concepts in communication of clinical laboratory data; Principles and practice of kinds-of-quantity and units; Requesting, generating, and transmitting clinical laboratory data; Choice and use of kinds-of-quantity for different examination purposes; Kinds-of-quantity of dimension one: SI unit 1; Kinds-of-quantity of dimension other than one; Kinds-of-property without dimensions of the ISQ; Index of abbreviations used for institutions and committees; Index of symbols for kinds-of-quantity and corresponding coherent SI units in clinical laboratory sciences.

There has been significant expansion and development in clinical laboratory sciences and, in particular, metrological concepts, definitions and terms since the previous edition of this book was published in 1995. It is of prime importance to standardize laboratory reports for reliable exchange of patient examination data without loss of meaning or accuracy. New disciplines have appeared and the interrelationships between different disciplines within clinical laboratory sciences demand a common structure and language for data exchange, in the laboratory and with the clinicians, necessitating additional coverage in this book. These new sections will be based upon recommendations published by various national, regional, and international bodies especially IUPAC and IFCC. This book groups and updates the recommendations and will be appropriate for laboratory scientists, medical professionals and students in this area.

This second edition of the Silver Book comes 20 years after the first edition and has been extensively reworked to cover modern metrological principles and some new techniques that are now used in clinical chemistry. The new text takes into account the latest ISO rules for terminology work [not the PAC (Pure and Applied Chemistry) rules] and, not surprisingly as one of the authors (RD) was the IUPAC representative on the Joint Committee for Guides in Metrology (JCGM) Working Group 2 for many years, the International Vocabulary of Metrology (VIM) [1]. By virtue of its membership of the JCGM, IUPAC is signed up to the VIM, although the Chemistry and Human Health Division is possibly the only part of the organization that has wholeheartedly embraced this standard. A section (4: Fundamental Concepts in Communication of Clinical Laboratory Information) stresses the need for a set of rules for transmission of information (4.1.2), and the whole work consistently applies a systematic approach. The perceived need to create a complete system of terms for the concepts in clinical chemistry has led to correct but sometimes awkward terminology. This raises the question of how much new terminology should be introduced if the existing, but not optimally systematic, terms are well used and known. The use of massic, entitic, kelvic, volumic and aeric correctly and systematically expresses kinds-ofquantity of dimension M-1, 1-1, T-1, L-3 and L-2 (see 5.4.6 for all denominator kinds of quantity), but I know of few chemists who call density volumic mass, or the Boltzmann constant entitic kelvic energy constant (although to be fair mass density and Boltzmann constant are, respectively, allowed synonyms). Well known, and acknowledged by the Green Book [2], is the clinical chemists preference for the short-form substance concentration for amount-of-substance concentration, rather than the recommended amount concentration. It will be interesting to see what the recommendation becomes if IUPAC succeeds in changing the name of amount of substance to chemical amount. However, the clinical chemists are not beyond improving on present accepted standards. I note the preference to hyphenate, against existing authority, amount-of-substance and kind-of-quantity. Section 5 is a short treatise on metrology, perhaps wasted on many readers, but which underpins the whole approach of the book. The Silver Book goes much further than the Green Book, perhaps where such a discourse might be expected, and is somewhat at odds with the Green Book, which does not mention kind of quantity at all, being happy to refer to quantity throughout. Section 6 on the transmission of clinical information revolves around the established NPU format for reporting data as Component—System; kind of property with various specifications [3]. It contains approaches for requesting and reporting and will be particularly useful as a concise aide memoire in clinical teaching. Section 7 Choice and Use of Kinds-of-property for Different Examination Purposes is an eclectic mix going through some fairly obvious quantities (e.g. amount ofsubstance and amount concentration) and then a subsection on thermodynamic quantities followed by optical spectroscopy, centrifugation, electrophoresis, and enzymology. Quite where modern techniques of magnetic resonance, chromatography/mass spectrometry for the –omics, DNA sequencing or immunoassays would be treated I do not know, but their absence gives the book an old-fashioned feel. About half the book is a list of kinds of quantity arranged in increasing dimension, starting with kinds of quantity of dimension 1 (Section 8) and then progressing to kinds of quantity of dimensions not 1 (Section 9). I have highlighted unusual systematic terms but at least some of the better known terminology is allowed. I note a serious error in the description of measurement uncertainty (6.10.5), which reads ‘‘The positive square root of such a variance is termed standard