SupplementaryAlignment: Whether this alignment is supplementary. Equivalent to SAM flag 0x800. Supplementary alignments are used in the representation of a chimeric alignment. In a chimeric alignment, a read is split into multiple linear alignments that map to different reference contigs. The first linear alignment in the read will be designated as the representative alignment; the remaining linear alignments will be designated as supplementary alignments. These alignments may have different mapping quality scores. In each linear alignment in a chimeric alignment, the read will be hard clipped. The alignedSequence and alignedQuality fields in the alignment record will only represent the bases for its respective linear alignment.