The set of keywords in a note together with a Separation of independent logical units span a context in which we look for related notes that put themselves into the same context. By sharing a context notes are in an implicit relationship with each other. This allows the user for Transformation of implicit into explicit relationships between notes generate knowledge in the next step.
The choice of keywords can be guided by the question: In what context do I want to have this note suggested again?
Tip: Use the singular. Make sure not to use different synonyms for the same context.