Use training records, permitted project summaries, internal qualification records, and other material that explains the knowledge accurately, after the company identifies what can be shared and what needs protection.
Choose evidence that answers the actual legal question
A reviewer needs enough detail to understand the process and the employee's role in it, not an unfiltered document dump. Confirm which examples establish the necessary facts and coordinate with legal counsel on how to handle anything genuinely sensitive, without removing so much detail that the claim becomes unsupported.
Firms that keep procedures under version control with named authors, record internal training with dates, and log which technician performed which proprietary step on which job have most of the file already. Where a document cannot be produced, obtain a written explanation and a statement from someone with direct knowledge, rather than leaving an unexplained gap in the chronology. Attach authentic project files, training emails, revision histories, access logs, or supervisor notes where available, while explaining ordinary gaps. Search internal wikis, ticket systems, and archived project folders before asking anyone to remember, because documents created at the time carry more weight than a summary written for the filing.