Nanounits
Nanounits are a conceptual submultiple of a base measurement unit, defined as one billionth (10^-9) of that unit. The term is not an official SI unit and has no universally adopted standard meaning beyond specifying a defined base unit. In practice, the nano- prefix is normally attached directly to the base unit (for example, nanometers or nanoseconds) rather than using a generic “nanounit” label. When nanounit is used, it should be clearly defined in context with the base unit to avoid ambiguity.
Notation and interpretation: If a nanounit is employed, 1 nanounit equals 10^-9 times the chosen base unit.
Usage and cautions: Nanounits appear primarily in theoretical discussions, simulations, or algorithms that require tracking quantities