Need more explanation on each ratings of Reliability & Credibility ???

Reliability

A source is assessed for reliability based on a technical assessment of its capability, or in the case of Human Intelligence sourcesHUMINT
HUMINT, short for HUMan INTelligence, is one of a series of Intelligence disciplines. NATO defines HUMINT as " A category of intelligence derived from information collected and provided by human sources."....
their history. Notation uses and Alpha coding, A-F:


Reliability of Source
A - Completely reliable
B - Usually reliable
C - Fairly reliable
D - Not usually reliable
E - Unreliable
F - Reliability cannot be judged



Credibility

An item is assessed for credibility based on likelihood and levels of corroboration by other sources. Notation uses a numeric code, 1-6.


Accuracy of data
1 - Confirmed by other sources
2 - Probably True
3 - Possibly True
4 - Doubtful
5 - Improbable
6 - Truth cannot be judged