This is the revision history for \s in <freenode.net:#regex>

factoid_idsubjectcopulapredicateauthornamespace
15798 \s is \s matches any whitespace character, such as a space or newline. \s is equivalent to [\r\n\t\f\v ], or [\p{Z}\h\v] in unicode mode (/u flag or (*UCP) pattern modifier). digitok
14654 \s is \s matches any whitespace character, like a space or linebreak. \s is equal to [\r\n\t\f\v ] (or [\p{Z}\h\v] in Unicode mode (/u flag or (*UCP) pattern modifier)) accolade
14653 \s is \s matches any whitespace character, like a space or linebreak. \s is equal to [\r\n\t\f\v ] (( except possibly for some Unicode stuff?? – edit this if you know )) accolade
14652 \s is \s matches any whitespace character, like a space or linebreak. \s is equal to [\r\n\t\f\v ] accolade