The following types of costs are allowable:
(a) Memberships in trade, business, technical, and professional organizations.
(b) Subscriptions to trade, business, professional, or other technical periodicals.
(c) When the principal purpose of a meeting, convention, conference, symposium, or seminar is the dissemination of trade, business, technical or professional information or the stimulation of production or improved productivity—
(1) Costs of organizing, setting up, and sponsoring the meetings, conventions, symposia, etc., including rental of meeting facilities, transportation, subsistence, and incidental costs;
(2) Costs of attendance by contractor employees, including travel costs (see 31.205-46); and
(3) Costs of attendance by individuals who are not employees of the contractor, provided—
(i) Such costs are not also reimbursed to the individual by the employing company or organization, and
(ii) The individuals attendance is essential to achieve the purpose of the conference, meeting, convention, symposium, etc.