‘Relevant administrative experience’ refers to any task you’ve performed in an administrative-type role that might be useful to the job that you’re applying for. You might have held a variety of different roles in the administrative realm, but look at the wording of the job description or posting to get a sense of what duties you will need to perform in this new role. Scan your work history, considering all the tasks and duties for which you were responsible. Include the ones you feel would be the most similar to the tasks you are expected to perform in a new role on your resume. This will make a strong argument for the effectiveness you will bring to the table for this new job because after all, if you were capable of doing it for one company, you’ll be able to do it again with a new one. It gives hiring managers the impression that they can be confident about your performance if they hire you.