Marks: Source, Define, Expand

Mark is the umbrella for a meaningful span you or Omphalis has identified. System-created Marks appear as quiet dotted underlines: Source traces a claim to supporting material, Define explains a term as it is used here, and Expand adds context without replacing the passage. Your highlights and notes are user-owned Marks.

System Marks reveal progressively: pause or focus first, then open the detail. Precision matters more than coverage. A missing Mark is less harmful than a confident but wrong one, while your own Marks preserve what mattered to you.