@List = sort {
    $a eq "one" and -1
 or $b eq "one" and 1
 or $a eq "two" and -1
 or $b eq "two" and 1   # no need to check if $a eq one
 or $a eq "thr" and -1
 or $b eq "thr" and 1
 or 0                   # advertising the default case
}