I have posted this before, but perhaps it is time to bring it out again.
These are the rules for the appointment of Shihan as promulgated by the Aikikai Hombu:
Rules for Appointment of Shihan
1. Rules for Appointment of Shihan
These Rules for Appointment of Shihan have been developed based on the provisions of Paragraph 15 and 16 of the Aikido World Headquarters' International Regulations, and are intended to supplement the said International Regulations.
Shihan is the title of Aikido instructor defined in Paragraph 15 and 16 of the International Regulations.
3. Appointment of Shihan
The Hombu appoints Shihan at its discretion pursuant to Paragraph 16 of the International Regulations.
4. Recommendation for Title Shihan
(1) An Aikido organization which has been given Official Recognition by the Hombu can recommend any of its instructors who meets the qualifications as a candidate for Shihan.
(2) To be qualified as a candidate for Shihan, he or she must fulfill the following conditions.
- In principle, have more than six years of experience teaching Aikido in his or her organization after obtaining 6th dan.
- Be proficient in the practice and instruction of Aikido.
- Be of good personal character.
(3) An individual person cannot recommend himself or herself. The recommendation should come from the person responsible for the relevant organization and be in written form. Recommendations can be submitted at any time of the year.
(4) For recommendation of a candidate, the form attached to these Rules must be used.
(5) The Hombu shall notify the relevant organization upon receipt of the recommendation, and inform the organization of the schedule for the examination of the document submitted. Upon immediate review of the submitted documents, the Hombu may judge a candidate as not qualified at this time for being considered for the title of Shihan, and in this case will notify the relevant organization accordingly.
5. Examination and Examination Committee for Appointment of the Title of Shihan.
(1) The examination of candidates based on the document submitted shall be conducted once every year at the Hombu. The date of the examination will be determined by the Hombu. The examination shall be comprised of a review of the submitted documents and a personal interview, if necessary.
(2) The Examination Committee for Appointment of Shihan shall be established by the Hombu.
6. Notification and Certificate of Appointment
After the examination, the Hombu shall notify, in written form, the relevant organization of the result of the examination. To the person appointed as Shihan, the Hombu will send a Certificate of Appointment.
The complete rules can be read here http://www.aikidoeast.com/aikidoeast/greetings/rules_for_appointment_of_shihan.html