This document specifies rules for the indication of the permissible deformation of a wavefront transmitted through or, in the case of reflective optics, reflected from an optical element or assembly in the ISO 10110 series, which standardizes drawing indications for optical elements and systems. This document is also applicable when using optical systems with general surfaces (ISO 10110-19). The deformation of the wavefront refers to its departure from the desired shape. The tilt of the wavefront with respect to a given reference surface is excluded from this document. There is no requirement that a tolerance for wavefront deformation is indicated.