The purpose of this technical note is to consolidate the notations used for describing parameters that pertain to neutron multiplicity mathematics relevant to various applications including nonproliferation, international safeguards, and criticality safety among others. The nomenclatures used in these techniques vary widely depending on the origin of the work and their applications. We aim to consolidate many of the previously used notations in a single document to enhance past, present, and future technical exchanges pertaining to neutron multiplicity. This will help avoid confusion in future publications and will facilitate wider application-independent advancements and utility of peer-reviewed findings. A brief introduction and history of neutron multiplicity counting is presented, followed by a summary of commonly used techniques in a variety of different applications. In each section, we present the notations used in previous publications for the reader’s reference.