47 CFR § 64.1002 - Investments and expenses.
(a) Investment and expenses not used and useful in the ordinary course. The following investments and expenses are presumed not used and useful (and thus unreasonable):
(1) Personal expenses, including but not limited to personal expenses for food and beverages, housing, such as rent or mortgages, vehicles for personal use, and personal travel;
(2) Tangible property not logically related or necessary to offering voice or broadband services;
(3) Political contributions;
(4) Membership fees and dues in social, service and recreational, or athletic clubs or organizations;
(5) Penalties or fines for statutory or regulatory violations; and
(6) Penalties or fees for late payments on debt, loans, or other payments.
(b) Non-customary investments and expenses. Unless customary for similarly situated companies, the following investments and expenses are presumed not used and useful (and thus unreasonable):
(1) Personal benefits, such as gifts, housing allowances, and childcare, that are not part of taxable compensation;
(2) Artwork and other objects that possess aesthetic value that are displayed in the workplace;
(3) Aircraft, watercraft, and off-road vehicles used for work and work-related purposes;
(4) Cafeterias and dining facilities;
(5) Charitable donations;
(6) Entertainment;
(7) Food and beverage expenses for work and work-related travel;
(8) Membership fees and dues associated with professional organizations;
(9) Scholarships; and
(10) Sponsorships of conferences or community events.