- Names</ulink>. The <structfield>message</structfield> is a human
- readable string describing the details. When no longer necessary,
- resources held by this structure should be destroyed with
- <function>sd_bus_error_free</function>.</para>
-
- <para><function>sd_bus_error_set</function> will return an
- errno-like negative value returned based on parameter
- <parameter>name</parameter> (see
- <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>).
- Various well-known D-Bus errors are converted to specific values,
- and the remaining ones to <constant>-ENXIO</constant>. Well-known
- D-Bus error names are available as constants
- <constant>SD_BUS_ERROR_FAILED</constant>, etc., listed above. If
- <parameter>name</parameter> is <constant>NULL</constant>, it is is
- assumed that no error occured, and 0 is returned. This means that
+ Names</ulink>. A number of common, standardized error names are
+ described in
+ <citerefentry><refentrytitle>sd-bus-errors</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ but additional domain-specific errors may be defined by
+ applications. The <structfield>message</structfield> field usually
+ contains a human-readable string describing the details, but might
+ be NULL. An unset <structname>sd_bus_error</structname> structure
+ should have both fields initialized to NULL. Set an error
+ structure to <constant>SD_BUS_ERROR_NULL</constant> in order to
+ reset both fields to NULL. When no longer necessary, resources
+ held by the <structname>sd_bus_error</structname>structure should
+ be destroyed with <function>sd_bus_error_free()</function>.</para>
+
+ <para><function>sd_bus_error_set()</function> sets an error
+ structure to the specified name and message strings. The strings
+ will be copied into internal, newly allocated memory. It is
+ essential to free the error structure again when it is not
+ required anymore (see above). The function will return an
+ <varname>errno</varname>-like negative value (see <citerefentry
+ project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>)
+ determined from the specified error name. Various well-known
+ D-Bus errors are converted to well-known <varname>errno</varname>
+ counterparts, and the other ones to <constant>-EIO</constant>. See
+ <citerefentry><refentrytitle>sd-bus-errors</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ for a list of well-known error names. Additional error mappings
+ may be defined with
+ <citerefentry><refentrytitle>sd_bus_error_add_map</refentrytitle><manvolnum>3</manvolnum></citerefentry>. If
+ <parameter>e</parameter> is NULL, no error structure is initialized,
+ but the error is still converted into an
+ <varname>errno</varname>-style error. If
+ <parameter>name</parameter> is <constant>NULL</constant>, it is
+ assumed that no error occurred, and 0 is returned. This means that