Reuse has a maintenance cost
A snippet can eliminate duplication, but it also introduces indirection. Writers must know where the content lives, how it is conditioned, where it appears, and what an edit may change.
The right goal is not maximum reuse. It is useful reuse.
Reuse the stable center
Shared properties, common procedures, repeated warnings, product-wide terminology, and consistent interface elements are strong candidates. Content that changes independently by audience or workflow may be safer as separate topics.
A good reuse strategy follows the product model rather than forcing every sentence into a universal component.
Make the architecture visible
Naming conventions, inventories, ownership rules, and short architecture notes prevent reusable content from becoming invisible machinery.
The system should remain understandable to the next writer, not only elegant to the person who built it.