The claimed profession’s own requirements apply. Do not combine favourable pieces of unrelated entries into a new standard.
Identify the actual category first
A second discipline may explain the applicant’s background without changing the required qualification. Evaluate the real job rather than selecting a profession solely because its wording is convenient.
A first review should separate the claimed profession from the applicant’s wider career story. Start with the employer’s current duty list, then compare each material duty with the listed profession and identify the credential that the entry actually calls for. The useful output is a short matrix: duty, profession fit, qualifying credential, licence issue, and missing proof. That matrix exposes a frequent problem: an employer wants a broadly capable person, but the offered role contains only a small amount of the professional activity claimed. Correct the job description before relying on it. Canadian or Mexican citizenship is required. A Canadian outside the country may seek TN classification during border inspection; an employer may instead use the applicable I-129 process. TN cannot be used to establish a US business that the professional solely or controllingly owns. Hypothetical example: a cartographer is offered a role to prepare flood-risk maps for a US engineering firm. Her letter also says she will answer general project calls. The decision record is the signed scope of work and the supervisor’s duty breakdown, not the broad title. If map analysis is primary and her geography degree meets the listed entry, the file can explain the incidental calls; if client coordination is the real job, the profession choice needs reconsideration.