What you are looking for is GR1304.14
https://www.usef.org/forms-pubs/nT3TlM3v0NA/gr13-competition-participants-and
No member of a steward or technical delegate’s family, nor any cohabitant, companion, domestic partner,
housemate, or member of a steward or technical delegate’s household, nor any of the steward or technical
delegate’s clients may take part as a trainer, coach, lessor, lessee, exhibitor, rider, driver, handler or vaulter at
a competition where the steward or technical delegate is officiating. In addition, the trainer or coach of a
Steward or Technical Delegate, or an individual from whom the Steward or Technical Delegate has
purchased or leased a horse within 30 days, may not participate (as rider, driver, owner, trainer or coach) at
a competition where the Steward or Technical Delegate is officiating. Technical Delegates and Stewards may
not officiate unless the client, trainer or coach relationship is terminated at least 30 days prior to the
competition.
But you should be aware that there is a rule change proposal (not yet approved as far as I know) that would change that to is permanently terminated at least 30 days prior .
I will come back and post a link to the rule change proposal.
OK, here is the link to the proposed rule change
file:///C:/Users/User/Downloads/049-22%20(4).pdf
The relevant part of the proposed change is
9. The following are not permitted to compete at the same competition as a Steward or Technical Delegate:
a. A Steward or Technical Delegate’s family member, cohabitant, companion, domestic partner,
housemate, or member of a Steward or Technical Delegate’s household;
b. A Steward or Technical Delegate’s client;
c. A Steward or Technical Delegate’s employee;
d. A Steward or Technical Delegate’s trainer or coach;
e. Any individual that has purchased or leased a horse from the Steward or Technical Delegate;
f. A horse owned by the Steward or Technical Delegate (including but not limited to syndicate and
partnership shares);
g. A horse trained by the Steward or Technical Delegate;
h. A horse sold by the Steward or Technical Delegate or by the Steward or Technical Delegate’s
employer; and
i. The above relationships are permitted if the relationship has been permanently terminated at least
30 days prior to the start date of the competition.