“An “F” rating does not necessarily mean that the source cannot be trusted, but that there is no reporting history and therefore no basis for making a determination.”Headquarters, Department of the Army (SUA) · FM 2-22.3 Human Intelligence Collector Operations · 2006 · FM 2-22.3 «Human Intelligence Collector Operations» (6 septembrie 2006), anexa B «Source and Information Reliability Matrix», paragraful B-1
A source's reputation does not confirm the information, and a lack of track record does not refute it.
Every report gets two grades, not one. The letter, from A to F, says how reliable the source is, judged on what it has reported before: A reliable, B usually reliable, C fairly reliable, D not usually reliable, E unreliable, and F cannot be judged, for a source with no track record. The figure, from 1 to 6, says how credible the information in this particular report is: 1 confirmed by other independent sources, 2 probably true, 3 possibly true, 4 doubtfully true, 5 improbable, and 6 cannot be judged. The grid is known as the Admiralty code, after its British origin, and the same logic of two separate grades appears in NATO intelligence doctrine. In practice: grade the source on what it has delivered so far, then the information on what it says now — internal logic, corroboration, consistency with everything else. The grades are kept apart because they can diverge: a B source can send a 5 report, and a new F source can bring something already confirmed. The method pays wherever many heterogeneous sources flow in, open sources included. The traps: reading F as liar — the manual says explicitly it only means no track record — and letting the source's reputation contaminate the grade of the information.
The next step is what you do with the grades over time. The evaluation is not a label but a testable promise: if a B source keeps sending reports that turn out right, its history moves toward A; if it errs, it slides down. The grades thus become a self-correcting record. An everyday example: a colleague who has always given you good information now says something that fits nothing else. You grade the source B, but the information 4. If it confirms, you raise both; if not, you lower the track record. The open question is how fast these grades should move — too slowly and a newly good source stays underrated, too quickly and one incident rewrites everything.
The grid only becomes useful when many people use it the same way. The ratings work as a shared language: your colleague reads "B3" and understands exactly what you meant, with no explanation. Without a shared grid, each evaluator invents their own scale, and reports cannot be added up. An everyday example: in a group of neighbors reporting problems to the town hall, if everyone describes sources however they like, nobody knows who is credible. If everyone uses the same letters and numbers, you can compare signals against each other and spot patterns. The grid turns personal judgments into something comparable and cumulative. The next step is what you do when two good ratings contradict each other.
Why it matters A single grade mixes two different questions and hides exactly the dangerous case: the good source that, this time, is wrong.