. . . . . "The Forerunners categorized the Technological Advancement of civilizations into Tiers. This system was later adopted by the Covenant. All life and civilizations in the Universe fall into one of the categories. The lower the Tier number, the more advanced the civilization's technology is/was. It should be noted that this is also a reference to Bungie's favorite number of 7."@en . . . "The Forerunners categorized the Technological Advancement of civilizations into Tiers. This system was later adopted by the Covenant. All life and civilizations in the Universe fall into one of the categories. The lower the Tier number, the more advanced the civilization's technology is/was. It should be noted that this is also a reference to Bungie's favorite number of 7."@en . "Technological Achievement Tiers"@en . . .