You search an edition for a term and find nothing. The result is real, but its meaning depends on the search. It may tell you less than the sentence “this idea was unknown” would suggest.
State the boundary
Write down the edition, language, section and search method. “No match for this English word in this translation” is a precise observation. It does not settle whether a related concept appears under different wording.
A damaged passage, an incomplete witness and a complete text that does not mention a topic are also different situations. Keep them apart instead of using “missing” for all three.
Ask what you expected to find
Would this kind of source normally discuss the subject? A short prayer and a legal document serve different purposes. Silence becomes meaningful only through an argument about what the evidence could reasonably be expected to contain.
For a personal reading exercise, make two lines: “what I checked” and “what remains unchecked”. This prevents the scope of a search from expanding unnoticed in later notes.
Make the next step specific
You might consult a glossary, another translation or a study of the relevant passage. Record which step actually resolves a question and which merely offers another lead.
The distinction matters especially when evidence survives unevenly. Our introduction to gaps in translations helps identify one kind of absence. A limited conclusion that can be checked is stronger than a universal claim built on a narrow search.