I signed my first SAFEA contract in September 1994 after having initially taught with a Z visa, but no RP for 21 days. The SAFEA contract does not include any probationary clauses. It needn't because you are effectively on probation during the whole duration of your contract. That is because if the employer isn't happy about your work performance, he/she has the right to point out your failings to you and give you 14 days or so to improve. Should you still disappoint at that time, you will be fired.

A stipulated probationary period means you can be fired at a particular time without given the opportunity to improve. The probationary period clause favors your employer, not you. You have no right to give up your job at that time if you don't like working there. It's not reciprocal!