(a)
Positions assignable
The Secretary may (with the concurrence of the agency, organization, or other body concerned) assign a member of the Service for duty—
(1)
in a non-Foreign Service (including Senior Executive Service) position in the Department or another agency, or with an international organization, international commission, or other international body;
(2)
with a domestic or international trade, labor, agricultural, scientific, or other conference, congress, or gathering;
(3)
for special instruction, training, or orientation at or with a public or private organization; and
(4)
in the United States (or in any territory or possession of the United States or in the Commonwealth of Puerto Rico), with a State or local government, a public or private nonprofit organization (including an educational institution), or a Member or office of the Congress.
(c)
Length of assignment
Except as otherwise provided in subsection (d)(5) of this section, assignments under this section may not exceed four years of continuous service for any member of the Service unless the Secretary approves an extension of such period for that member because of special circumstances.