Hello comrades!
There is a regular rule excluding this character set: *{}\/[]#@&<>
Here is the expression itself: /^(?!.*\{\}\\/\[\]#@&<>$)(.*)$/
It gives an error: Warning: preg_match (): Unknown modifier '\' in /path_to/index.php on line 485
Please tell me where this extra backslash.

~^(?!.*\{\}\\/\[\]#@&<>$)(.*)$~- Edward