The used letters are:
B,C,F,G,H,M,N,P,Q.
The scale of estimate is the following
(using the X as example):

"x" , "X" , "X"* , "X"** , "X"***

"x" = Soft perception;
"X" = Moderate;
"X"* = Decided;
"X"** = Strong;
"X"*** = Very strong.

These letters are surely precursors of EQs and volcanic eruptions,but not for many years the N.E.I.C. knowing,I based my calculations only on vague notices of newspapers and radio.
Now,to not go in rough mistakes,however I'll publish its giving explanation only about sure things enough.Meanwhile I'll intensify the studies drowing great advantage by N.E.I.C.
Here what I can say about varied precursors:

"B" = it predict from 1 to 5 days an EQ about 6.0 6.5.The percentage of chance I judge around 70%.

"C" = this signal precedes of 2 or 3 days every EQ,but I will use it only in notable cases.

"C+>"= it precedes swarm of shockes or magma getting up.

"C->"= it precedes a volcanic eruption(Etna in particular) with 60 hours of advance and followes the magmatic flux always with 60 hours of advance.About Etna,to giving a measure to the power of the flux,I add an index as:
(power 0.5) = poor
(power 1.0) = quite good
(power 1.5) = good
(power 2.0) = very good

"F" = it precedes from 1 to 7 days a moderate EQ, may be of volcanic origin.

"G" = it is like the spikes of Diane Pope,now,I must to study it better.

"H" = it precedes about 2 days an EQ of 4.5 or 5.0 as far 500Km around Naples.

"M" and "N" = its precede swarm of shockes in the same zone or a long EQ formed by more united shockes,from 2 to 7 days.I do not yet know the difference of the two signals.

"P" and "Q" = I have not yet well identified.

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