My question is, what’s the point? Spreading Savathuns Song? Almost all Guardians are infected with it. It’s spread through the City and is in the Tower being sung. A neat puzzle that seems to be nothing but a filler mystery.

Since those below have already mentioned Savathûn’s Song I’ll tackle the other thing. IKO-223 is just the hidden designation for Ikora. It’s the format Hidden agents use to identify themselves in messages.

From what I understand (and that’s not loads), the mistakes that have been found in the lore entries translate to a hexadecimal code, which gives some letters. If you apply the letters to a musical scale, it plays Savathuns Song. From Reddit by Teletheus: The Musical Message in Martian Missives Several folks have posted about the typographical errors in the Martian Missives lorebook, and more specifically how the those typos (which are directly acknowledged and referenced in the final page) appear consistent across various translations of the game. More notably, folks have reported how the typographical errors—across translations—also appear to fall adjacent to characters that are all hexadecimal values—which are also consistent across translations. I put together a full write-up on /r/DestinyLore explaining what it appears to be… but the short version is, it looks like “sheet music” encoded in hexadecimal values. The first half would be Savathûn’s song with a slight twist at the end… and the second would be identical to the new WQ theme. Is the WQ theme actually the second half of Savathûn’s song? Did she encode her song in hexadecimal values with the intent of our Ghost subconsciously picking up the song? Of course, theoretically, I guess this could be a coincidence. But the number of coincidences required would seem to make that possibility incredibly unlikely. (I wouldn’t be surprised if there’s more to this we’re still missing, though!) I want to give credit to u/RescueCPR, u/beastintheomlet, u/LunaTG, and u/Rephaim6131, all of whom raised points that sent me down these various rabbit holes and helped bring this theory together. I also want to give credit to everyone who went through those lore pages to find and identify the various typos (especially across translations) and commented on their consistency and their apparent pattern.