In 451 or 450 Pericles carried a law confining Athenian citizenship to those of Athenian parentage on both sides. No source provides any background to this proposal; it is not even clear whether it was retrospective.
A high school diploma or GED is enough to get started as an office clerk. It is important to have some office skills, such as typing, good phone skills, word processing, etc. Most training is done on the job.
The preferable schooling requirement needed to be a medical office assistant is a certificate or an associate's degree in medical office assisting. Programs are offered at community colleges, universities, and vocational schools and provide training in both common administrative tasks and skills unique to medical office settings.