You must be using a translator. The maker is Rich. A. Herder, not Rich. A. Shepherd.
Most of the stamp marks found under the grips on S84/98 III bayonets are random marks put there by assembler, the meaning of which is known only to the assembler and lost to time. The exception is when a bayonet has been refurbished by the Germans, and there may be a number(s), letter(s) or any combination of, stamped there and possibly elsewhere on the bayonet to keep track of parts when disassembled and reassembled. There can also be a WaA stamp and/or the serial number of the bayonet ( or part of it) stamped under the grips