41 C.F.R. § 304-2.1
The following definitions apply to this chapter:
Employee means an appointed officer or employee of an executive agency as defined in 5 U.S.C. 105 , including a special Government employee as defined in 18 U.S.C. 202 , or an expert or consultant appointed under the authority of 5 U.S.C. 3109 .
Meeting(s) or similar functions (meeting) means a conference, seminar, speaking engagement, symposium, training course, or similar event that takes place away from the employee's official station. "Meeting" as defined in this chapter does not include a meeting or other event required to carry out an agency's statutory or regulatory functions such as investigations, inspections, audits, site visits, negotiations or litigation. "Meeting" also does not include promotional vendor training or other meetings held for the primary purpose of marketing the non-Federal sources products or services, or long term TDY or training travel. A meeting need not be widely attended for purposes of this definition and includes but is not limited to the following:
Non-Federal source means any person or entity other than the Government of the United States. The term includes any individual, private or commercial entity, nonprofit organization or association, international or multinational organization (irrespective of whether an agency holds membership in the organization or association), or foreign, State or local government (including the government of the District of Columbia).
Payment means a monetary payment from a non-Federal source to a Federal agency for travel, subsistence, related expenses by check or other monetary instrument payable to the Federal agency ( i.e., electronic fund transfer (EFT), money order, charge card, etc.) or payment in kind.
Payment in kind means transportation, food, lodging, or other travel-related services provided by a non-Federal source instead of monetary payments to the Federal agency for these services. Payment in kind also includes waiver or discount of any fees that a non-Federal source collects from meeting attendees (e.g., registration fees), but does not include waivers or discounts of an employee's fees on the day(s) they are participating in the meeting or similar function as a speaker, panelist, or presenter.
Travel, subsistence, and related expenses (travel expenses) means the same types of expenses payable under chapter 301 of this title, the Foreign Affairs Manual (FAM), and the Joint Travel Regulations (JTR) for transportation, food, lodging or other travel-related services for official travel (e.g., baggage expenses, services of guides, drivers, interpreters, communication services, hire of conference rooms, lodging taxes, laundry/dry cleaning, taxi or TNC fares, or the cost of utilizing an innovative mobility technology company, etc). These expenses also include conference or training fees (in whole or in part), as well as benefits that cannot be paid under the applicable travel regulations, but which are incident to the meeting, provided in kind, and made available by the meeting sponsor(s) to all attendees. For example, this definition as applied to this chapter would allow an employee or spouse to attend a sporting event hosted by the sponsor(s) in connection with the meeting that is available to all participants. The Foreign Affairs Manual is available at https://fam.state.gov. The Joint Travel Regulations are available at https://www.defensetravel.dod.mil/site/travelreg.cfm.
41 C.F.R. §304-2.1