The Lab classification implements some coding principles used in the international statistical classifications (ICD-10): code is formed of the alphabetical and the digital values. The alphabetical parts are the English titles abbreviations; the principle of hierarchical coding is kept – the digits mark the depth of the specification.

Fifteen chapters in accordance with biological materials divide the laboratory procedures classification. Each chapter is built in compliance with the internal logical structure. Chapters related to biological fluids are divided into 3 main parts: analyses measuring the physical properties, chemical and biochemical analyses, microscopic analyses. The chapter I - Blood is an exception; additionally the hematology and blood coagulation studies, determining the ability of the blocks, are separated in the structure of this chapter. The bacteriological microbiology chapter combines bacteriology and virology researches, mycology and parasitology tests. This chapter covers the basic diagnostic tests, without identification of specific pathogenic agents. Pathogenic agents could be mentioned using appendixes, which are used in alphabetical order.