If the application suggests that the use of terms such as "about", "approximately" or "substantially" extends either the interval claimed by a value and/or range outside the error margins of the measurement system or the structural unit beyond the manufacturing tolerances, then the wording becomes vague and undefined, i.e. the application does not fulfil the requirements of Art. 84, because its presence prevents the invention from being unambiguously distinguished from the prior art with respect to novelty and inventive step.

For example, if the application suggests that an icosagon (20-sided polygon) is also a "substantially circular circumference" for a metal tray realised by a CNC waterjet cutting machine, this renders the scope of the claims unclear because: