4.7 Terms such as "about", "approximately" or "substantially"
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 or any other tolerance that the skilled person would take into consideration in the technical field concerned, then the wording of the claims becomes vague and undefined. This leads to an objection under Art. 84 because the presence of this wording prevents the subject-matter of the claims 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:
(i)the tolerance indicated by the application is outside the tolerance of the manufacturing method (a CNC waterjet cutting machine approximates a circular circumference by using a polygon with hundreds of sides); and
(ii)if an icosagon is also a "substantially circular circumference", what about an enneadecagon (19-sided polygon) or an octadecagon (18-sided polygon)? When does a polygon stop being a "substantially circular circumference"? How can this be assessed objectively by the person skilled in the art?