SGA-A

.               - Any Character Except New Line
\d              - Digit (0-9)
\D              - Not a Digit (0-9)
\w              - Word Character (a-z, A-Z, 0-9, _)
\W              - Not a Word Character
\s              - Whitespace (space, tab, newline)
\S              - Not a Whitespace (space, tab, newline)

\b              - Word Boundary (it is a word)
\B              - Not a Word Boundary (it is part of a word)