Manning was a Starfleet crewperson in the 2260s, a member of the USS Enterprise's security crew. Manning was qualified to wear the uniforms of both a command division and operations division officer. He was assigned to the guard detail for a mummy the Enterprise recovered, but was rendered unconscious by that charge. Later, Manning joined a landing party to Rifas-L as a security guard, and was aboard the Galileo when it crashed on Tristas. (TOS comics: "The Mummies of Heitius VII", "The Perfect Dream", "The Final Truth")
With the exception of the regular Enterprise crew, Manning is the most prolific recurring character in the Gold Key/Whitman comic series, with three appearances. In "The Mummies of Heitus VII", Manning wore a gold command division uniform, but identified himself as a member of security. He had dark hair that was receding. By "The Perfect Dream", he wore an operations division redshirt and had gone gray, lost more hair, and grown a mustache. In "The Final Truth", he was back in his gold shirt and had a fuller head of brown hair.