Relative Terms

Date Published

Note: The information in this part only applies to:

  • standard patent applications with an examination request filed on or after 15 April 2013.
  • innovation patents with an examination request filed on or after 15 April 2013.
  • innovation patents where the Commissioner had not decided before 15 April 2013 to examine the patent.  

For all other standard patent applications/innovation patents, see Relative Terms.

A specification may describe an invention by way of relative terms.  This does not usually present a problem with the construction of the specification, provided the skilled addressee can determine what is encompassed by the claims.

In particular, a complete specification does not lack a clear enough and complete enough disclosure merely because some experimentation of a routine nature is necessary to perform the invention. In Poseidon Industri A.B. v Cerosa Limited (1982) FSR 209, the patent related to a diving suit with a "close fit", such that only a "minimum air layer" could form between the suit and the diver's body. It was held that the patent was not bad for insufficiency, even though the specification made use of a relative term which did not describe how much room there should be between the diver and the suit. In this case, "a little ordinary trial and error" would be sufficient to ascertain the satisfactory minimum layer of air.

See also Catnic Components Limited v Hill & Smith Limited (1982) RPC 183.

Although the principles in the above cases were decided under the grounds of “full description”, they apply equally to considerations of clear enough and complete enough disclosure.