A strategy document defines a strategy and how to put it into practice. Will Larson has written extensively on this topic with a focus on technical strategy. He proposes a process of1:

Policy: what does the strategy require or allow?
Operation: how is the strategy enforced and carried out, how do I get exceptions for the policy?Refine: what were the load-bearing details that informed the strategy?
Diagnose: what are the more generalized trends and observations that steered the thinking?Explore 2: what is the high-level, wide-ranging context that we brought into creating this strategy?

A few examples of strategy documents from Will Larson:

1.
Will Larson. Steps to Build an Engineering Strategy. https://lethain.com/components-of-eng-strategy/ (2025).
2.
Will Larson. Exploring for Strategy. https://lethain.com/exploring-for-strategy/ (2025).
3.
Will Larson. Writing an Engineering Strategy. https://lethain.com/eng-strategies/ (2023).