There are many canons of claim construction.
- Claims should be construed as of the time of the invention.
- Limitations should be given their “ordinary meaning” as understood by a skilled artisan.
- Claim construction begins with dictionary, encyclopedia, and treatise definitions.
- Dictionaries, treatises, and encyclopedias are critical to claim construction.
- Claim differentiation applies to presume a difference in meaning and scope when different words or phrases are used in separate claims.
- Preamble terms are not claim limitations.
- Limitations in the specification may not be read into the claims.
- Express limitations in the specification should be read into the claims.
- Claims should be construed to cover preferred embodiments.
- Claims should be construed to uphold their validity.
The immediate question is whether the en banc decision in Phillips v. AWH will (i) present a cleanly revised list or (ii) simply add another rule to the list. (Listing adapted from a presentation by Kevin Casey).