Write claims for the competitor and the courtroom

Your real reader is an opponent

An examiner reviews your claims to decide whether to allow them. A competitor reads them looking for a way out. WIPO tells drafters they "should always try to ensure that competitors, either actual or potential, cannot circumvent the claimed invention", and warns that rivals will read the file for "damaging admissions" (WIPO Patent Drafting Manual).

Selden's car patent is the cautionary tale. As one secondary account tells it, a court reportedly held his patent valid but not infringed by Ford's different engine (JD Supra). We have not read that opinion, but the point holds as a warning: a valid patent that a rival can step around does little.

A judge decides what your words mean

Deciding what claim words mean is called claim construction, and it belongs to the court (Markman). Subsidiary facts found along the way are reviewed for clear error (Teva v. Sandoz). The specification "is the single best guide to the meaning of a disputed term" (Phillips, quoted in MPEP § 2111). Your examples and definitions will be used to read your claims, whether or not you meant them that way.

Amendments have a price

The doctrine of equivalents can reach a substitute that falls outside a claim's literal words. It applies element by element (Warner-Jenkinson).

Festo adds the price. Narrowing a claim during examination "may be presumed to be a general disclaimer of the territory between the original claim and the amended claim". The presumption is rebuttable for unforeseeability, tangentiality or another reason (Festo). Graham made the same point in 1966 (Graham v. John Deere). Before you give ground to an examiner, ask what you are giving away.

Claim so that one actor infringes

Inducement means encouraging someone else to infringe, and there is no inducement without direct infringement (Limelight v. Akamai). One law firm summarizes the 2015 Akamai decision this way: an entity answers for others' steps only if it directs or controls them or they form a joint enterprise (Hunton). We have not read that opinion.

In our judgment, the safest habit is to write each method claim from one actor's point of view. If a user's phone does one step and a separate company's server does the next, you may have a claim that nobody infringes alone.