Add ELEMENT to PL header tag

SAMv1.tex

@@ -317,7 +317,7 @@ \subsection{The header section}
   & {\tt PG} & Programs used for processing the read group.\\\cline{2-3}
   & {\tt PI} & Predicted median insert size.\\\cline{2-3}
   & {\tt PL} & Platform/technology used to produce the reads. \emph{Valid values}:
-  {\tt CAPILLARY}, {\tt DNBSEQ} (MGI/BGI), {\tt HELICOS}, {\tt ILLUMINA}, {\tt IONTORRENT}, {\tt LS454}, {\tt ONT} (Oxford Nanopore), {\tt PACBIO} (Pacific Biosciences), and {\tt SOLID}.
+  {\tt CAPILLARY}, {\tt DNBSEQ} (MGI/BGI), {\tt ELEMENT}, {\tt HELICOS}, {\tt ILLUMINA}, {\tt IONTORRENT}, {\tt LS454}, {\tt ONT} (Oxford Nanopore), {\tt PACBIO} (Pacific Biosciences), and {\tt SOLID}.
   This field should be omitted when the technology is not in this list (though the {\tt PM} field may still be present in this case) or is unknown.\\\cline{2-3}
   & {\tt PM} & Platform model. Free-form text providing further details of the platform/technology used.\\\cline{2-3}
   & {\tt PU} & Platform unit (e.g., flowcell-barcode.lane for Illumina or slide for SOLiD). Unique identifier.\\\cline{2-3}
@@ -1442,6 +1442,7 @@ \section{SAM Version History}\label{sec:history}
 \subsection*{1.6: 28 November 2017 to current}
 
 \begin{itemize}
+\item Add {\tt ELEMENT} to the list of {\tt @RG PL} header tag values. (June 2022)
 \item Clarify that header field tags must be distinct within each line, and that the ordering of both header fields and alignment optional fields is not significant. (Jun 2021)
 \item Clarify the meaning of TLEN when secondary alignments are present. (May 2021)
 \item Bin calculation changed for alignment records whose CIGAR strings consume no reference bases: like unmapped records, they are considered to have length one (rather than zero). (Jan 2021)