Conversations from the Universe

Conversations from the Universe, also known as the "Esoteric" manual, is a booklet included in the Halo 2 Limited Collector's Edition. It contains various conversations, letters and logs from characters in the Halo universe.

Overview
Conversations From the Universe originated as a booklet included in limited edition copies of Halo 2 alongside a Covenant-themed manual. The booklet was later made available for download as a digital PDF on the Xbox website, before being posted in their entirety on Halo Waypoint.

The Conversations hint at several plot threads and mentions, for the first time, that were later picked up on years after their introduction. Such examples include;
 * The first and only mention of the existence of the Sharquoi until later confirmation in a Canon Fodder and the focus of the 2016 novel Halo: Envoy.
 * Hints at other visitors to Installation 04 by 343 Guilty Spark, later depicted in the terminals of Halo: Combat Evolved Anniversary.
 * Some of the first usage of Covenant species' proper names (Sangheili instead of Elite, Unggoy instead of Grunt etc.) - until this point, Halo media had typically referred to the Covenant as Elites, Grunts, Jackals and Hunters.

Trivia

 * C. Errera, the soldier who picked up the conversation between two Grunts, is a reference to Claude Errera, one of the lead founders of halo.bungie.org. He later appears directly in the canon in Halo: Reach, where random Army troopers recruited under the "Fireteam" mechanic may have his name.