The program doctext is designed so that it is easy to add additional
formatting commands of the form . command.
In fact, you can define your own formatting commands. This is done in two
steps. First, you add formatting commands using a command definition file
(See See section Customizing the Output Format) and include those definitions with
the -defn filename command-line argument. You can then invoke your
new commands by using .f<command name> in the source file. For
example, if the file indent.def contains
in \begin{quotation}%n
out \end{quotation}%n
you can use
.fin
This text will be within a LaTeX quotation environment
.fout
in the source file.
Other commands beyond those described in this document may be added in the future, so you should not rely on any particular behavior of . character. For example, .seealso has been added to provide a common reference for related information. If you need some particular formatting option that you cannot achieve with the .f approach, please send the suggestion to gropp@mcs.anl.gov.