What is the Codex Astartes?

[Octavulg]

Rewrote would seem the obvious way to refer to that.

 

Not that the idea seems bad, just that that doesn't seem to be what he would have been talking about.

[Techmarine Data007]

Or he could be referring to his own contributions to the Codex. Though the tone would seem to claim more personal familiarity than that.

[Captain Idaho]

"'I know what the Codex says,' snapped Agemman. 'I wrote enough of it.'

I know it's a bit late, but I took the semester off from 40k and I'm just now reading through the five pages of threads I missed; I'll throw in my two cents here. I haven't read the novel so I couldn't say for sure, but isn't it possible that the Ultramarines copy the manuscript as a devotional exercise, much as medieval monks copied and illuminated the Bible? Couldn't that be what Agemman was referring to?

 

Good to have you and your monkey back mate. I'd imagine that the Ultramarines do have exercises that are relating to copying it etc. but I got the impression Agemman wasn't refering to that in that passage. He definitely seemed like he was referring to the fact he wrote parts of it, as he was indignant at the implication he didn't understand the Codex tenants, which is a bit of an over reaction if he was merely copying it out!