NOTES
Because SAM has optional tags that have different meanings in different
programs, careful usage is required in order to have proper output. The
"xs" tag in bwa-sw is used to show the suboptimal score, but in PacBio SAM
(
blasr(1))
it is defined as the start in the query sequence of the alignment.
When
-smrtTitle is specified, the xs tag is ignored, but when it is not
specified, the coordinates given by the xs and xe tags are used to define
the interval of a read that is aligned. The CIGAR string is relative to
this interval.