Hydran individuals could be dubbed (i.e. granted knighthood) if they achieve a rank high enough in the Hydran Royal Navy or the Hydran Civil Service. Individuals that served in the Royal Navy would be granted knighthoods when they achieved the rank of ensign or higher.
Lyran knights were granted their nobility title by letters patent (such as winning the final phase of the Lyran Imperial Science Fair Tournament) and, also, when they were granted command of a ship of the line. (RIS Bouteina: "Degree of Liberty")