The letter should describe the actual professional duties in the vocabulary of the listed profession and explain the internal title separately. A title alone neither qualifies nor disqualifies a role, but a letter that only repeats an unlisted title leaves the reviewer nothing to match.
Describe duties, then explain the title
Employers name positions for internal reasons: pay bands, reporting lines, collective agreements. A hospital system might call the position a clinical nutrition coordinator when the work is dietetics as the professional list describes it. Ask the employer to write the duties first, in specific terms, and to state the proportion of time spent on each. Then add a short line explaining that the internal title is administrative. Avoid the opposite error of rewriting the job so that it matches a listed profession the applicant will not actually perform, because the description has to remain true once the person starts. If the duties genuinely fall outside every listed entry, the letter cannot fix that and a different classification needs to be considered. Keep the supervisory and administrative components clearly separated from the professional practice they accompany.
Hypothetical example: An environmental engineer is offered a remediation-design role after an employer has used a broad internal title, project specialist. The first review produces a duty-by-duty outline, a credential inventory, and a list of missing originals. The university transcript settles what was studied, while the signed letter settles who will employ the person, where the professional work occurs, and how long it is requested for. Obtain translations or evaluations only when the actual credential or issuing language requires them. An attractive résumé, unsigned draft, or job advertisement does not carry the same evidentiary weight as records traceable to their issuer.