Closes #24

core/frame_info.h

@@ -26,7 +26,7 @@ struct FrameInfo {
     std::uint32_t canId = 0U;                    /**< Normalized CAN identifier. */
     bool isExtended = false;                     /**< true for extended frame. */
     std::uint32_t pgn = 0U;                      /**< J1939 PGN if applicable. */
-    bool hasPgn = false;                         /**< true if PGN was derived. */
+    bool hasPgn = false;                         /**< Explicit J1939 opt-in; pgn is derived from canId. */
     std::uint8_t dlc = 0U;                       /**< Frame payload length. */
     std::string transmitter;                     /**< Transmitter ECU name. */
     std::string comment;                         /**< Optional frame comment. */