Special name for an argument to a [proc] - if it's last in the argument list, it will contain a list (possibly empty) of all the remaining arguments.

'''example args'''

#CLASSES
Class Club -parameter {id {name unknown}}
Class Player -superclass Club -parameter {{name unknown} {position unknown}}

#PROCS
Player proc show_players '''args''' {
  if { [string length $args] == 0} {
    puts "Show players DB"
    foreach p [my info instances] {
      puts "[$p name] [$p position]"
    }
    return
  }

  set pos [string toupper $args]
  puts "Players with postition $pos:"
  foreach p [my info instances] {
    foreach char [split $pos {}] {
      if {[string first $char [$p position]] == 1} {
        puts "[$p name] [$p position]"
        break
      }
    }
  }
}