I haven't written this document yet, but in the meantime you can look at the documentation for the jtagconvert.tcl library, which implements format conversions. The section Comments on Formats is particularly useful; it mentions some of the major shortcomings of jstools' conversions to various formats.
Thanks to Miguel Santana <santana@imag.fr> for permission to use the /reencodeISO procedure from his a2ps program when converting rich¡text to PostScript.