#1
what does it mean when there's an @? As an example if you look at the this site's tab for Beethoven's Fur Elise, version 1, 1st interpretation, there are a couple parts where there are @'s. there are artificial harmonics used too but they're marked as 14A for example.
#2
Its being used to indicate the 'Repeat' symbols.
usually it would be marked with two 'o''s like this:

o
o

I dont know why this is done differently, but why not i say.
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