Lawyers often will write "pursuant to [name of law or regulation]" without expecting the phrase to be the source of controversy.  But language is an inherently ambiguous tool and lawyers will, if adequately feed, argue about just about anything.  In a recent Ninth Circuit Court of Appeals case, several hundred thousand dollars turned on the meaning of "pursuant to an Act of Congress".  Swoger v. Rare Coin Wholesalers, 2015 U.S. App. LEXIS 17614 (9th Cir. Cal. Oct. 8, 2015).

The case arose from an alleged agreement by the defendant coin owners to pay the plaintiff coin expert for information proving that "their coin was the first legal-tender coin struck pursuant to an Act of Congress".   However, the coin expert had a problem because the act, An Act Regulating Foreign Coins, and For Other Purposes", ch. 5, 1 Stat. 300 (1793), governed foreign, not domestic, coins and the coin in question was struck in the United States.  The coin expert argued that this was irrelevant because the coin "conformed" to the Act.  The Court of Appeals, however, found that conformance to the Act did not make the coin legal tender.

The Court of Appeals is therefore interpreting "pursuant to" as something different than "in conformance to" even though that is one commonly understood meaning of "pursuant to".  The Court of Appeals' view seems to be that an action is "pursuant to" the Act only if it is an action covered by the Act. For example, a contract might require that a party give a specific notice (e.g., a notice of default) in a specified manner (e.g., registered mail).  A party might give a notice not specified in the contract by registered mail.  The notice would be given in conformance to the contract but it would not be given pursuant to the contract.