Sufficiency of Disclosure

In one line

The specification must teach a skilled reader how to do the invention, and it must teach the best way the applicant knows.

In the wording a student can write in an exam: section 10(4)(a) and (b) of the Patents Act, 1970 require a complete specification to fully and particularly describe the invention and its operation or use and the method by which it is to be performed, and to disclose the best method of performing the invention which is known to the applicant and for which he is entitled to claim protection.

Why insufficiency is fatal

Because the disclosure is the price. Chapter 20 works the bargain. A patentee who takes twenty years of exclusivity and gives a document nobody can work from has taken without paying.

And because the Act enforces it three times over. Insufficiency is a ground of opposition under sections 25(1)(g) and 25(2)(g), a ground of revocation under section 64(1)(h), and, in the form of failure to disclose the best method, a further ground under section 64(1)(h) as well. Chapters 570 and 1030 work them.

The result is that a patent can be perfectly novel, perfectly inventive and still worthless. Sufficiency is a wholly separate attack, and a defendant who cannot win on the prior art will very often plead it.

The four requirements packed into section 10(4)

One: fully and particularly describe the invention. What the invention is.

Two: describe its operation or use. What it does and how it is used.

Three: describe the method by which it is to be performed. How to make or carry out the invention. This is the enablement requirement, and it is the heart of sufficiency.

Four: disclose the best method known to the applicant. Not any workable method, but the best one the applicant knows and is entitled to claim protection for.

The fourth is peculiar to a small number of systems and India is one of them. Many countries require enablement and not best method. India requires both, which makes an Indian specification a fuller document and gives a defendant an extra line of attack.

The test: who reads it, and when

The reader is the person skilled in the art, the same notional person as in the inventive step enquiry, and chapter 420 works that. They bring the common general knowledge of the field and no inventive capacity.

The time is the filing date of the complete specification. A specification that was insufficient when filed is not saved by later knowledge, and one that was sufficient then is not made bad by later advances.

The standard is undue burden. The skilled reader may have to do routine work: ordinary trial, calibration, selection among known alternatives. They may not have to invent, and they may not have to carry out a research programme.