/^       # anchored to the beginning of the string
 \w+     # one or more word characters (a word)
 \s*     # zero or more whitespace characters
 =       # an equals sign
 \s*     # zero or more whitespace characters
 \w+     # one or more word characters (a word)
 \s*     # zero or more whitespace characters
 \,      # a comma (you actually don't need to backslash this)
 \?      # a question mark
 \w+     # one or more word characters (a word)
    /x;