[new_hackers]

For a professional engineer's license, you have to demonstrate competence and have 4 letters of recommendation from PEs who have either managed you directly, or have overseen your work. So there is not a requirement that you (as a budding prospective PE) may never work for someone who isn't a PE, however it does limit your ability to achieve your own license. Therefore, there is a desire from the younger engineers to seek out PEs to work under.