Definition
A specific subsection of Title 14 of the Code of Federal Regulations, Part 61, Section 315, paragraph (c), item (5). This regulation addresses the privileges and limits of a Sport Pilot certificate holder, and item (c)(5) specifically prohibits a sport pilot from carrying a passenger or property for compensation or hire.
Plain English
It is the federal rule that says a sport pilot is not allowed to be paid to fly people or cargo somewhere. It is one of the boundary lines that separates sport pilot flying from commercial flying.
Context Anchor
You may see this citation in light-sport aircraft training material, especially where sport pilot privileges and limits are listed.
Derivation
The citation reads from the outside in. '14 CFR' is Title 14 of the Code of Federal Regulations, the body of rules covering aeronautics. '61' is the part dealing with pilot certification. '315' is the section about sport pilot limits. '(c)(5)' points to a specific paragraph and item within that section. Reading a regulation citation is just narrowing down to the exact line you need.
Why Pilots Care
Knowing this rule prevents a sport pilot from inadvertently entering airspace where they are not authorized, avoiding enforcement action and safety risk.
Intuition Check
Do not read this as a general night-flying rule for all pilots. This specific paragraph is about the night-flying limit for sport pilots.
Example Sentence 1
The flight instructor reminded the sport pilot student that 14 CFR 61.315(c)(5) prohibits carrying a passenger for compensation, no matter how short the flight.
Example Sentence 2
Because the destination airport had a control tower, the pilot confirmed compliance with 14 CFR 61.315(c)(5) prior to departure.