Changes

<td>[[:alnum:]]<td>Alphanumeric - any number or letter. Equivalent to [a-z], [A-Z] and [0-9]</td>

<td>[[:alpha:]]<td>Alpha - any letter. Equivalent to [a-z] and [A-Z]</td>

<td>[[:blank:]]<td>Space or Tab. Equivalent to [\\t] and [ ]</td>

<td>[[:cntrl:]]<td>ASCII Control Character</td>

<td>[[:digit:]]<td>Numeric. Equivalent to [0-9]</td>

<td>[[:graph:]]<td>Any character with the exception of space</td>

<td>[[:lower:]]<td>Lower case letters. Equivalent to [a-z]</td>

<td>[[:print:]]<td>Any printable character</td>

<td>[[:punct:]]<td>Characters that are neither control characters, nor alphanumeric (i.e punctuation characters)</td>

<td>[[:space:]]<td>Any whitespace character (tab, new line, form feed, space etc)</td>

<td>[[:upper:]]<td>Upper case letters. Equivalent to [A-Z]</td>

<td>[[:xdigit:]]<td>Any hexadecimal digit. Equivalent to [A-F], [a-f] and [0-9]