; (D) derives more than 1 percent of the individual's annual income from a significant Fund service provider; (E) derives more than 5 percent of the individual's annual income from any Fund service provider; or (F) fails to meet such other criteria as are specified by the Secretary to ensure the independence of the board of directors. (3) Multiple trusteeships No individual may serve on the board of trustees of more than 1 USA Retirement Fund unless the Secretary receives attestation from the board of trustees of each applicable USA Retirement Fund and the individual that, at the time of appointment, there is no reasonably foreseeable conflict between the duties of such individual to the participants in each applicable USA Retirement Fund. In no case may an individual serve on the boards of trustees of more than 3 USA Retirement Funds. (4) Trustee qualifications Each trustee of a USA Retirement Fund shall attest that the trustee is knowledgeable of the trustee's duties and responsibilities as a fiduciary of a USA Retirement Fund. The Secretary may require by regulation such other qualifications and documentation as may be necessary to ensure that trustees are suitable and qualified. Such requirements may include those related to education, training, and minimum competency standards. (5) Trustee selection and removal (A) In general Each board of trustees of a USA Retirement Fund shall establish written procedures regarding the appointment, removal, and replacement of trustees on the board. Such procedures shall— (i) take effect after adoption by the majority of the board of trustees; (ii) be readily available to participants; (iii) provide participants with a reasonable opportunity to comment on, or participate in, the trustee selection process