#I saw a post about Category 5 Jon incidents and I will not let the fandom ignore this.

[panoptical]

MAG 123:

ARCHIVIST (under his breath) Where did the – (sighs) [SOME SHUFFLING AS HE LOOKS THROUGH PAPERS/WHATEVER’S ON HIS DESK.] (salt) Coma, great! Let’s rearrange his office. Sleeping people don’t need – pens.

MAG 140:

BASIRA But I think – Have you got a pen? ARCHIVIST Uhh – Yeah, i-in the drawer. [BASIRA OPENS THE DRAWER.] BASIRA Ah, John. What’s this? [SHE PICKS SOMETHING UP.] ARCHIVIST Hm? Oh. That’s… I, th, uh – that’s my rib. BASIRA (Pythagorean theorem, volume of a cone) Right. [SHE PUTS IT BACK.] ARCHIVIST Yep. BASIRA And… the jar of ashes. ARCHIVIST (stress.exe) Not – not, m,mine – I mean, it belongs to me, I, I, I guess, but it’s not – stationery is in the, uh, other drawer.

The implication of these two scenes is:

Jon got some pens after MAG 123 and put them in his desk drawer. Alright.

He uses a separate discrete drawer for storing both Prentiss' ashes and his own rib, which contains no stationary.

The use of "other drawer" implies these are either the only or the biggest drawers in the desk.

Conclusion: Jon has two drawers in his office desk that are organized by either "office supplies" or "human remains".