The $* identifier left the help file a while ago, after while loop were introduced, it's now an undocumented identifier.

$* is extremely powerful because is it much faster than using a while loop on a list of token, consider the following:

var %list a b c d,%a 1
while ($gettok(%list,%a,32)) {
echo -a $v1
inc %a
}

this can be written as