--- loncom/html/adm/help/tex/Authoring_Output_Tags.tex	2017/01/23 20:29:42	1.25
+++ loncom/html/adm/help/tex/Authoring_Output_Tags.tex	2017/02/01 21:18:43	1.26
@@ -17,8 +17,30 @@ exp, abs, logten, log, ln, sqrt, sgn, st
   <chem>O2 + 2H2 -> 2H2O</chem>
 \end{verbatim}
 will be rendered:
-
 $\mathrm{O_2} + 2\,\mathrm{H_2} \to 2\,\mathrm{H_2O}$
+
+\textbf{Syntax Description}
+\begin{itemize}
+\item Reactants are separated from products by `\texttt{->}'.
+\item Individual reactants and products are separated by `\texttt{  +}' (leading space is obligatory).
+\item Numbers preceding the first symbol of a chemical specie are considered to be stoichiometric coefficients.
+\item Numbers appearing after the first symbol of a chemical specie are considered to be subscripts.
+\item Superscripts are initialized by `\texttt{\^{}}' and terminated by a space.
+\item Ionic charges are superscripts composed of a number followed by a sign (i.e. `\texttt{\^{}2+}').
+\end{itemize}
+
+\textbf{More examples}
+\begin{itemize}
+\item $\mathrm{Ca}(\mathrm{NO}_3)_2$ is written as:\\
+\texttt{Ca(NO3)2}
+\item $\mathrm{OH}^- + \mathrm{H_3O}^+ \to 2\mathrm{H_2O}$ is written as:\\
+\texttt{OH\^{}- + H3O\^{}+ -> 2H2O}
+\item $[\mathrm{Co}(\mathrm{H_2O})_6]^{2+} + 4\mathrm{Cl}^- \to [\mathrm{CoCl_4}]^{2-} + 6\mathrm{H_2O}$ is written as:\\
+\texttt{[Co(H2O)6]\^{}2+ + 4Cl\^{}- -> [CoCl4]\^{}2- + 6H2O}
+\item $^3_1\mathrm{H} + ^2_1\mathrm{H} \to ^4_2\mathrm{He} + ^1_0\mathrm{n}$ is written as:\\
+\texttt{\^{}3 1H + \^{}2 1H -> \^{}4 2He + \^{}1 0n}
+\end{itemize}
+
 \item \textbf{num}\index{num}\index{format number}: Typesets a number formatted in scientific notation, fixed point, fixed point with commas, fixed point with commas and dollar sign, or in significant digits. 
 \begin{verbatim}
   <num format="2E">31454678</num> results in 3.15 x 10^7