>>9243408 lb
4 letters are used
There are 4 bases in RNA or DNA codes.
j and J are little and big but related
Guanine is like a Cytosine molecule with more added on.
Uracil is not that different from Cytosine
Adenine has more pieces like Guanine
So I think
J = G
j = C
y = U
m = A
G…AU…UC @ C…U…UCCU
Now, the … may be a Single Nucleotide Polymorphism so only one base
Then @ would be some number of bases
In other words, this specifies 2 markers in the RNA of SARS-CoV-2 that people might want to look at.
And if you agree more or less with this, but think I have the coding wrong, with only 4 possibilities you could try all variations and search for them.
This is easiest for a Bioinformatician who has the tools.
I have a copy of one source of the genome with T instead of U and a quick check shows 78 possible sites with TCCT that could match the rest of this marker.