This is the explanation of your regex,
The regular expression:
(?-imsx:^([a-zA-Z0-9\/\-\%\:\[\]\{\}\|\;\<\>\?\,\*\!\@\#\$\(\)\^_`~]*)$)
matches as follows:
NODE EXPLANATION
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(?-imsx: group, but do not capture (case-sensitive)
(with ^ and $ matching normally) (with . not
matching \n) (matching whitespace and #
normally):
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^ the beginning of the string
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( group and capture to \1:
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[a-zA-Z0-9\/\- any character of: 'a' to 'z', 'A' to
\%\:\[\]\{\}\|\;\< 'Z', '0' to '9', '\/', '\-', '\%', '\:',
\>\?\,\*\!\@\#\$\( '\[', '\]', '\{', '\}', '\|', '\;',
\)\^_`~]* '\<', '\>', '\?', '\,', '\*', '\!',
'\@', '\#', '\$', '\(', '\)', '\^', '_',
'`', '~' (0 or more times (matching the
most amount possible))
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) end of \1
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$ before an optional \n, and the end of the
string
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) end of grouping
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