5.5.3.6 Description Construed as a Technical Document

Also in this Chapter:

• 5.5.3.1 Words are given plain meaning;
• 5.5.3.2 Read the specification as a whole;
• 5.5.3.3 Purposive Construction;
• 5.5.3.4 Dictionary Principle;
• 5.5.3.5 Reject the absurd;
• ​​​​​​​5.5.3.7 Errors, Mistakes, Omissions.

Key Legislation: 

Patents Act:

• s7 Novelty, inventive step and innovative step  
• s7A Meaning of useful  
• s18 Patentable inventions
• s40 Specifications 
• s41 Specifications: micro-organisms  

Related Chapters:

• 5.6.7.1 Claims are Clear and Succinct
• 5.6.4 Citations: Prior art base and construction of prior art
• 5.6.5 Novelty, Whole of Contents, and Secret Use
• 5.6.6 Inventive Step
• 5.6.7 Full Disclosure, Sufficiency, Clarity, Support and Usefulness (s40)
• 5.6.8 Patent Eligible Subject Matter (Manner of Manufacture)

The description is primairily a technical disclosure

The description is to be construed as a technical document. This means it only needs to be comprehensible to readers who are skilled in the relevant technical field.

A higher standard of clarity may be necessary in the claims (see 5.6.7.1 Claims are Clear and Succinct).

The body of the specification, apart from the preamble, is there to instruct those skilled in the art concerned in the carrying out of the invention. Provided it is comprehensible to, and does not mislead, a skilled reader, the language used is seldom of importance (Decor Corp v Dart Industries 13 IPR 385).

​​​​​​​The description is more particularly a technical disclosure and is construed with regard to the person skilled in the art (Unifloc Reagents Ltd v Newstead Colliery Ltd 60 RPC 165):

"But the body of the specification is a document giving working instructions to working men – highly skilled working men with high technical qualifications, no doubt, in the case of many modern fields of industry. It is to such persons and not to grammarians or lawyers or even expert witnesses that specifications are considered to be addressed, and they ought not, I think, to be construed as if they were Acts of Parliament or conveyances or wills or instruments of that description. The working man in whose hands the specification is assumed to have been placed must also, I think, be assumed to be a man who is going to try to achieve success and not one who is looking for difficulties or seeking failure."

However, reference may be made to the claims to resolve an ambiguity in the body of the specification (United Shoe Machinery Corp’s Application [1939] 57 RPC 71).