because if you remove the . then it would become cs access $chan add|del|list $2-

if ($1 == .add) || ($1 == .del) || ($1 == .list) {
cs access $chan $remove($1,.) $2-
}

??

How can $1 be equal to 3 things? :s

Your brackets are a little messed up there. It should be:

on *:INPUT:#: {
  if ($1 == .eI) && (!$2) {
    mode $chan +eeeIII $address($me,9) $me $address($me,2) $address($me,9) $me $address($me,2) | Halt
  } 
  if ($2) && ($1 == .eI) {
    mode $chan +eeeIII $address($2,9) $2 $address($2,2) $address($2,9) $2 $address($2,2) | Halt
  }
  if ($1 == .add) || ($1 == .del) || ($1 == .list) {
    cs access $chan $remove($1,.) $2-
  }
  if ($1 == .add) && ($3 isnum) {
    mode $chan $iif($3 == 3,+v)  $iif($3 == 4,+h-v) $iif($3 isnum 5-9,+o-hv) $iif($3 > 9,+ao-hv) $str($2 $+ $chr(32),5)
  }
  if ($left($1,1) == +) || ($left($1,1) == -) {
    $iif($remove($1,-,+) isalpha,mode $chan $eval($1-,2))
  }
  if ($1 == .mode) && (!$2) {
    mode $chan $2- | halt
  }
}