- <listitem><para>the parametrized address of the tile, in the spirit of C printf format, with 4 "%s" fields for left, right, bottom and top (eg. "http://hostname:8111/load_and_zoom?left=%s&right=%s&bottom=%s&top=%s")</para></listitem>
+ <listitem>
+ <para>the parametrized URL to open in the spirit of C printf format, with up to 7 "%s" values. e.g. <literal>http://hostname/getfile?lat=%s&lon=%s</literal></para>
+ <para>The order and meaning of these parameters is given by the url_format_code below</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>url_format_code</term>
+ <listitem>
+ <para>A string describing the parametrized URL substitution parameters, each character represents how to translate each term.</para>
+ <para>B = Bottom of the current view i.e. minimum latitude</para>
+ <para>L = Left of the current view i.e. minimum longitude</para>
+ <para>T = Top of the current view i.e. maximum latitude</para>
+ <para>R = Right of the current view i.e. maximum longitude</para>
+ <para>A = center lAtitude of the current view</para>
+ <para>O = center lOngitude of the current view</para>
+ <para>Z = OSM Zoom value of the current view. See <ulink url="http://wiki.openstreetmap.org/wiki/Zoom_levels">Zoom Levels</ulink></para>
+ <para>Thus for the url example above then the format code should be <emphasis>AO</emphasis></para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>file_type</term>
+ <listitem>
+ <para>This value is passed on for the -i parameter in interfacing with GPSBabel.</para>
+ <para>If it is not defined then the returned file is interpreted internally as a GPX file.</para>
+ <para>Possible values such as 'kml', 'mapsource' etc.. can be used. See <ulink url="http://www.gpsbabel.org/capabilities.html">GPSBabel File Formats</ulink> for the full list.</para>
+ </listitem>