[modeller_usage] can salign output a "structural mapping" of residues

As a first (naive) question on that mailing list, I wonder if (and how) it is possible to retrieve residues that are structurally aligned as a result of a aln.salign() run (object aln being of type alignment). To precise my question, I know a (multiple) sequence alignment is produced as a result of this salign command and can be output with aln.write(), but I am more concerned by the possible mapping of residues in the structural alignment, that might not be apparent in the sequence.

--Ben.S