Source reliability and confidence.
Liberty91 rates every piece of information it learns from on two axes: how reliable the source is, and how credible the data is. It uses the NATO Admiralty scale, a long-standing intelligence convention, and applies the resulting rating as a weight when it adds information to a knowledge base. More reliable, more credible information carries more weight.
What is the Admiralty scale?
The Admiralty scale (also called the Admiralty code) rates two things independently:
| Source reliability | Information credibility | ||
|---|---|---|---|
| A | Completely reliable | 1 | Confirmed by other sources |
| B | Usually reliable | 2 | Probably true |
| C | Fairly reliable | 3 | Possibly true |
| D | Not usually reliable | 4 | Doubtful |
| E | Unreliable | 5 | Improbable |
| F | Cannot be judged | 6 | Cannot be judged |
A rating is written as a letter and a number. For example, B2 means a usually reliable source reporting information assessed as probably true.
Reliability belongs to the source, credibility to the occurrence
The two axes attach to different things, and keeping them apart is what makes the rating useful.
Reliability (A to F) is a property of the source. A government CERT and an anonymous forum post do not carry the same weight, and that judgement holds across everything they publish rather than being re-argued story by story. Liberty91 starts each source at a grade appropriate to its class, then adjusts it on evidence: a source caught reporting something that does not hold up is downgraded, and one that is repeatedly borne out is promoted.
Credibility (1 to 6) is a property of the Threat Event, the real-world occurrence itself, and it is computed across every report attached to it. More reliable sources push it up. Independent corroboration pushes it up. A reliable source disputing the account pushes it down. Reports that merely mention the occurrence in passing count for less than ones that assert or corroborate it.
Two consequences worth knowing. Credibility moves as reporting develops, which is what you want while a story is still unfolding. And independence is assessed rather than assumed: several outlets running the same wire copy are collapsed together instead of being counted as separate confirmation, so circular reporting cannot manufacture confidence that is not there.
How Liberty91 uses the rating
When an event is deemed relevant to an Intelligence Requirement, a threat entity, asset, or supplier, the platform assesses the source and the data and assigns an Admiralty rating. That rating becomes a weight in the knowledge base, so well-sourced information shapes the analysis more than weak or unconfirmed reporting. This is one of the ways the platform keeps its knowledge grounded and reduces hallucination in the products it generates.
You can read more about the original decay and weighting research on the CIRCL Decaying Indicators of Compromise work that informs Liberty91's IOC scoring. See also IOC enrichment and decay scoring.