It should identify original authors, approvers, the applicant’s own technical contribution, and the U.S. need.
Show the chain of responsibility
Take the elements one at a time and name the document that proves each, because a technical manual on its own proves almost none of them. The standard those exhibits have to reach is special knowledge of the organisation's own product, service, equipment, techniques or management, or advanced knowledge of its processes and procedures; that knowledge need not be unique, secret or patented, but it must be more than skill any experienced practitioner in the trade would hold. For the corporate relationship: articles, share registers or a group structure chart showing the ownership link, plus something showing both entities trading, such as recent invoices, payroll or a lease.
For the qualifying year abroad: dated employment letters, payroll summaries or T4s covering the twelve months, and a duty description written at the time rather than for the petition. For the knowledge itself: the procedure's revision history naming the author and approver of every version, the deviation reports or change requests this person raised or closed, training records showing who was certified on what, and audit or corrective-action files that show the method being applied. Where three people wrote a manual, say so and mark the transferee's own revisions; claiming sole authorship of a document whose approval block names someone else is the quickest way to lose credibility on every other point.
Finally, describe the receiving assignment in its own document: the line, its current configuration, the decisions the transferee will make, and, if any work happens at a client's site, who supervises it there.