Knowledge of the employer's own methodology, proprietary data or internal procedures counts. General technical competence with widely used equipment does not, however deep it runs. The petition must show what the knowledge consists of, how it was acquired within the organization, and why the American entity cannot readily obtain it elsewhere.
The test is about the organization's knowledge, not the worker's seniority
Petitions fail most often because they describe an excellent technician rather than a distinctive body of company knowledge. The definition points at special knowledge of the petitioning organization's product, service, research, equipment or techniques and their application in international markets, or an advanced level of knowledge of the organization's own processes and procedures. Applied to instrumentation work, that distinction is usually visible on the ground.
Certification on a manufacturer's analyzer platform is portable and is held by technicians at every competitor. A validation methodology the employer wrote, a correction database compiled from its own field history, and internal procedures for reconciling readings across mismatched installations are not portable. The evidence should therefore include the internal documents themselves, training records showing how long the knowledge takes to transfer, and a plain statement of what the American operation would have to do without the transferee.