This is also a point in the Warhammer 40,000 Lore. some 18,000 years from now, Humanity advanced science and technology to nearly godlike extremes, and suffered

This is also a point in the Warhammer 40,000 Lore. some 18,000 years from now, Humanity advanced science and technology to nearly godlike extremes, and suffered a fully regressive collapse lasting close to another 10,000 years. The fallout of this means that all 'modern' technology is operated upon by tech-priests, who blindly perform rituals upon equipment to ensure it's 'machine spirit' is satisfied. This ensures that the equipment will properly function. All knowledge as to how the most advanced equipment operates is lost - all that's left is how to produce some of the lesser pieces. Caches of templates to produce standardised equipment are highly treasured. These ancient and supremely advanced caches produce extremely detailed designs for the entire supply chain required to build a single item. A template to provide for a slightly sharper knife is as desirable to the Imperium as another template to provide for a 55 Meters tall armoured war machine.