+---------------------------- start of character class
  |            +--------------- END of character class !!!
  |            |
  |            |+-------------- characters and metacharacters
  |            ||               from here on
  |            ||
  |            ||     +-------- START-OF-STRING anchor !!!
  |            ||     |
  |            ||     | +------ 0-or-more quantifier
  |            ||     | |
  |            ||     | |++---- empty capture group
  |            ||     | |||
  |            ||     | |||+--- literal ] character
  |            ||     | ||||
  v            vv     v vvvv
m/[#@':;><,.{}[]=!"£$%^&*()]/
    ^               ^
    |               |
    |               +--- interpolated scalar $%
    |
    +------------------- interpolated array @'