Clinical and Laboratory Standards Institute document EP36—Harmonization of Symbology and Equations provides readers with a list of the most common statistical symbols and formulas to describe testing procedures and statistical analyses. The purpose is to provide a standardized symbology for use in CLSI documents that will benefit the CLSI readership as well as the volunteers participating on CLSI committees. Symbols are based on International Organization for Standardization guidelines and the most recent CLSI documents. They are grouped in different categories related to performance evaluation testing. CLSI document development committees and working groups are expected to adhere to these symbols unless there are strong arguments for deviating from these recommendations.

The purpose of this document is to provide recommendations on harmonized symbols and notations that describe concepts, procedures, and test approaches used in statistical equations and models within CLSI documents. 

The intended users of this document are CLSI volunteers and staff involved in developing standards, guidelines, and related products. It is intended that future CLSI documents will converge to a more standardized symbolism and notation by taking into account the recommendations made in this document. This document is not intended to cover all mathematical symbols and operations nor all statistical procedures used or referenced in CLSI documents.