A more thorough explanation:

The Conformity Act was a federal statute passed in 1872 that required the practice and procedure in federal district courts to conform to the practice and procedure used by state courts for similar cases, except in equity and admiralty matters. However, the Federal Rules of Civil Procedure replaced the Conformity Act in 1938.

Even when there was conformity, it was not always mandatory. The federal judge could disregard a state practice that would hinder the administration of the law or justice. This led to conflicting decisions and confusion.

For example, if a federal district court in California was hearing a case involving a breach of contract, the Conformity Act would require the court to follow the same procedures as the California state court for similar cases. This would include the rules for filing a complaint, serving the defendant, and presenting evidence.

However, if the federal judge believed that a particular state practice would not serve the ends of justice, they could choose to disregard it. This gave the judge some discretion in how they applied the Conformity Act.