41 C.F.R. § 304-3.8 – Registration fee waiver and payment in kind considerations.

(a) Acceptance of a waived or discounted registration fee from the non-Federal sponsor of the event is not a payment in kind for the day(s) employees are participating as a speaker, panelist, or presenter.
(b) Acceptance of a waived or discounted registration fee is a payment in kind for the days employees only attend the event (i.e., on the day(s) employees are not participating as a speaker, panelist, or presenter).
(c) Lodging, transportation, meals, event tickets, or other similar items of value provided by a non-Federal source are a payment in kind. If these types of expenses are included in a registration fee that is waived or discounted on the day(s) employees are participating as a speaker, panelist, or presenter, the employee may accept them only with their agency's approval in accordance with this chapter.