Few will have the greatness to bend history itself, but each of us can work to change a small portion of events. … It is from numberless diverse acts of courage and belief that human history is shaped. ...
In US: must be an attorney licensed and in good standing in any state, territory or DC.
Outside US: must be a lawyer or equivalent (eg counselor, barrister, advocate, solicitor), duly educated and licensed/accredited and in good standing.
As a general rule, experienced and currently practicing lawyers, and those teaching law in the legal academy, are more likely to be admitted.