Keep the limited confirmation and identify other reliable evidence of the actual work. Do not expand the employer’s statement beyond what its author knows.
Distinguish the source of each experience fact
A contract, dated deliverable or knowledgeable former colleague may help explain a period, depending on the facts and requirements. Record who can confirm the duties, dates and applicant’s contribution. Preserve confidentiality and distinguish team work from personal authorship.
The goal is an assessable record, not a guarantee that a portfolio replaces the required experience evidence or that every proposed substitute will be accepted. Hypothetical example: A Trois-Rivières book-cover illustrator has an early client who will verify payment dates but cannot discuss manuscripts protected by confidentiality. Preserve that limited letter, then pair it with redacted invoices, dated delivery records and a clear explanation of the illustrator’s personal contribution.
A first review should map each claimed duty and date to the record that actually supports it. Do not ask the former client to certify artistic details the client does not know. The usual problem is a reference letter that sounds comprehensive but conflicts with contracts or omits the relevant period.
Sequence the file from the least disputed date evidence to the work-description evidence, and explain any remaining limitation directly instead of filling it with an unsupported portfolio claim.