Text in 4.9 dealing with multiple exclusion shall be adjustment for C+, allowing for #pragma once:
The convention is an all uppercase construction of the full namespace, the file name and the h suffix.
For a file named AntennaRx.h:
alternatively, #ifdef can be still used in existing code:
#ifndef LSST_ANTENNA_RX_H // referring to file: AntennaRx.h
#endif // LSST_ANTENNA_RX_H