No universal secrecy or uniqueness requirement applies. The actual special or advanced knowledge must meet the standard and connect to the proposed U.S. work.
Describe the knowledge precisely
A supported explanation of what the employee learned and applied is more useful than an absolute claim the records cannot prove. Ask the foreign supervisor to identify a concrete organization-specific process, the applicant’s learning path, and a U.S. task that requires that knowledge.
Match each assertion to training records, change logs or technical work product. A qualifying transfer also generally requires one continuous year abroad in a qualifying capacity during the preceding three years. Hypothetical example: a satellite-antenna technician knows a proprietary calibration sequence but the U.S.
assignment is described only as general installation. The calibration records, training history and work order reveal whether special knowledge is actually needed. Broad claims about talent fail when they do not connect an employee’s personal knowledge to the proposed work.
L-1B time is limited to five years. End with a precise statement of the knowledge, its source and the U.S. task requiring it.
That statement should be checkable against actual records, rather than against a generic claim that the employee is valuable.