Quoted By:
"Chapters [not descended from Guilliman's geneseed] are disciples who owe their genetic inheritance to another Primarch, but follow the Codex Astartes as keenly as their divergent heritage allows. While primarily composed of successor Chapters, this group also includes several Chapters of the First Founding - notably the Imperial Fists, White Scars and the Raven Guard. These chapters can never be Ultramarines, for their gene-seed is not that of Roboute Guilliman. Nevertheless, they will ever aspire to the standards and teachings of the great Primarch."