What is Salient term?
Verified 5 August 2026
Salience is essentially inverse document frequency: a term appearing in a handful of documents carries far more identifying information than one appearing everywhere. These are the terms users search when they want something specific rather than something similar.
They are also the terms semantic retrieval handles worst, since an identifier has no meaningful embedding neighbourhood.
This is the failure mode a selective index has to get right, and unlob commits to it as a guarantee rather than a best effort: an exact identifier that is in the index stays findable, and does not quietly disappear as the corpus is compacted. Use the term filter to require one.
How unlob handles this: The term filter
Common questions
What is Salient term?
A salient term is a distinctive, low-frequency token that identifies specific content — an error code, an identifier, a proper noun — as opposed to common vocabulary.
How does Salient term work in practice?
They are also the terms semantic retrieval handles worst, since an identifier has no meaningful embedding neighbourhood.
See it working
The free tier is 10,000 requests a month with no card — enough to test any of this against your own queries.