United Nations Space Command Emergency Priority Order 098831A-1

Summary
Command issued by Vice Admiral Preston Cole to help stop the Covenant from finding Earth. Basically, it is an order to not allow the Covenant to retreve data that contains the location of Earth, and forbids retreating vessles from setting course to Earth, because the Covenant may be able to track their movement.

Excerpt from Halo: The Fall of Reach:

Article 1
United Nations Space Command Emergency Priority Order 098831A-1

To safeguard the Inner Colonies and Earth, all UNSC vessels or stations must not be captured with intact navigation databases that may lead Covenant forces to human civillian population centers.

If any Covenant forces are detected:

1. Activate selective purge of databases on all ship-based and planetary data networks. 2. Initiate triple-screen check to ensure all data has been erased and all backups neutralized. 3. Execute viral data scavengers (Download from UNSCTTP://EPWW:COLEPROTOCOL/Virtualscav/fbr.091) 4. If retreating from Covenant forces, all ships must enter Slipstream space with randomized vectors NOT directed toward Earth, the Inner Colonies, or any other human population center. 5. In case of imminent capture by Covenant forces, all UNSC ships MUST self-destruct.

Violation of this directive will be considered TREASON and pursuant to UNSC Military law articles JAG 845-P and JAG 7556-L, such violations are punishable by life imprisonment or execution.

Article 2
This article is never directly stated, though Captain Keyes uses it while his ship is crashing on Installation 04. Captain Keyes says "I'm initiating the Cole Protocol, Article 2. We're abandoning the Autumn. That means you, too, Cortana." Later saying, "Destruction or capture of a shipboard AI is absolutely unacceptable."

This implies that Article 2 states something about abandoning a vessel and landing it when its weapons are destroyed and there is no hope of rescue for the crew should they self-destruct the vessel. It also absolutely forbids the destruction or capture of a human AI by the Covenant.

Subsection 7
No [captured] Covenant craft may be taken to human controlled space without an exhaustive search for tracking systems that could lead the Covenant to Human bases.

Few had even heard of subsection seven because it was little more than a technicality, before the Ascendant Justice was captured. Because the humans could not completely search the ship, they instead planned to take it to Reach and try to return with a more prepared team.