Drafting the Patent Specification
Structure and function
A specification must contain a title, description, one or more claims, drawings where necessary, and an abstract. The description must be clear enough for the skilled person to perform the invention, and must disclose the best method known to the applicant. Candidates must distinguish the description's role (enabling and supporting) from the claims' role (defining the monopoly).
Claims architecture
Draft an independent claim that is as broad as the prior art permits, then layer dependent claims as fallback positions. Traps: a claim broader than the description supports; omnibus claims; relative terms such as "substantially" or "about" that render scope uncertain; and functional language that fails to teach how the function is achieved.
Consistency and antecedent basis
Every term in a dependent claim must have antecedent basis in the claim from which it depends. Inconsistency between description and claims (for example, a feature described as essential but omitted from the independent claim) invites a s 40 challenge and undermines fair basis.
Worked example
Suppose the invention is a valve with a magnetic seat. A poor independent claim recites "a valve with improved sealing". A better claim recites the structural features that achieve the seal - the magnetic seat, the cooperating ferromagnetic ring, and the specified gap range - while a dependent claim narrows the gap to the exemplified range. The rule of thumb: claim structure that produces the advantage, and keep the advantage in the description as the problem solved.