Committer Acknowledgement from Apache Community

Hi,
I recently got a request from a PMC member for formal recognition that they
are an Apache Committer.
The individual is not a member of the foundation.
Apparently the request came from the individuals employer as they would
like to know for sure that the individual is actually a project committer.
What is the process here?
Can I (as project chair) write a letter of acknowledgement and pass it on?
Are there any more formal resources we can leverage to provide the project
committer with?
Thank you very much.
Lewis