Routines are always described in lower-case letters. A reference to a routine described in the same document is always of the form
\routine{routinename}
and a reference to a routine defined in some external hypertext document
is always of the form
\extroutine{routinename}
.
A routine description starts with a \section, \subsection, etc.
command:
\section{Routine routinename}
For correct operation of the \routine and \extroutine commands
the label must always start with rout-:
\label{rout-routinename}
The routine is then described in a straightforward manner using environments
defined in the isnas style.
\begin{Description}
description.....
\end{Description}
\begin{Heading}
\begin{verbatim}
subroutine janse(a,b)
\end{ verbatim}
\end{Heading}
\begin{Params}
\item [par1] description
\item [par2] description
\end{Params}
\begin{Input}
requested input
\end{Input}
\begin{Output}
output generated by the routine
\end{Output}
\begin{Seealso}
references to other routines, data structures, documents.
\end{Seealso}
Note, the heading of the subroutine should always start at position 1
in the LaTeX source file.