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Date Published

A "disclaimer" is a statement separate from the claims (usually just before the claim pages), declaring that certain matter is to be excluded from them. The words "subject to the foregoing disclaimer" may be present in the preamble to the claims, however the absence of these words is not objectionable.  This differs from a proviso, where the matter to be excluded is specified within the text of a claim.

Both disclaimers and provisos are commonly used to distinguish a generic invention from the prior publication of a particular entity that falls within the scope of the generic invention.

The existence of a disclaimer should be clearly indicated, similar to the situation where a ‘dictionary definition’ of a term is being relied upon. As a disclaimer modifies the scope of the claims, any lack of clarity in a disclaimer must be reported on as a lack of clarity in the claims.

See British Celanese Ltd. v Courtaulds Ltd. (1933) 50 RPC 259 at pages 273 to 284.

Where a disclaimer or proviso makes reference to another patent specification or other document which may be amended over time (such as a GenBank entry or a webpage), the general considerations in relation to references apply (see Inclusion of References and Cross-References).

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