Well, if the coder wants to have a different error message when $sockerr equals to 3, then the method is quite good (though, imho, too much ifs are used here).

Have in mind that, for each on sockread trigger, $sockerr is allocated only one value(0 = no error, 1-n = error), so checking it at different stages won't change its value.

In the example you posted, the coder just wanted to have the error message for $sockerr = 3 displayed. Now, the while loop is not necessary when sockreading sockets. I would do something like this instead.

Code:
on *:sockread:VIPCheck*: {
  if $sockerr {
    echo -tac Highlight * $iif(($v1 == 3),error on connected socket occurred for $sockname $sock($sockname).wserr,Unknown sock error for $sockname)
    return
  }
  var %data
  sockread %data
  if (!$sockbr) return
  elseif (($regex(%data,/<user(?: (opped|voiced)="true"|())>([^<]+)<\/user>/)) && ($istok($gettok($sock($sockname).mark,2-,32),$regml(2),32))) {
    if (($regml(1) == opped) && ($me isop $gettok($sock($sockname).mark,1,32)) && ($regml(2) ison $v2) && ($v1 !isop $v2)) .mode $v2 +o $v1
  }
}


Hope this helped.

Cordialement

tropnul