+/****f* silcutil/SilcBufferFormatAPI/SilcBufferFormatFunc
+ *
+ * SYNOPSIS
+ *
+ * typedef int (*SilcBufferFormatFunc)(SilcBuffer buffer,
+ * void *value,
+ * void *context);
+ *
+ * DESCRIPTION
+ *
+ * Formatting function callback given with SILC_STR_FUNC type. The
+ * `buffer' is the buffer being formatted at the location where the
+ * SILC_STR_FUNC was placed in formatting. The function should call
+ * silc_buffer_enlarge before it adds the data to the buffer to make
+ * sure that it has enough space. The buffer->head points to the
+ * start of the buffer and silc_buffer_headlen() gives the length
+ * of the currently formatted data area. It is also possible to use
+ * silc_buffer_format with `buffer' which will enlarge the buffer if
+ * needed.
+ *
+ * The `value' is the value given to SILC_STR_FUNC that is to be formatted
+ * into the buffer. It may be NULL if the function is not formatting
+ * new data into the buffer. The `context' is caller specific context.
+ * Returns -1 on error and length of the formatted value otherwise, and
+ * 0 if nothing was formatted.
+ *
+ ***/
+typedef int (*SilcBufferFormatFunc)(SilcBuffer buffer, void *value,
+ void *context);
+
+/****f* silcutil/SilcBufferFormatAPI/SilcBufferSFormatFunc
+ *
+ * SYNOPSIS
+ *
+ * typedef int (*SilcBufferSFormatFunc)(SilcStack stack,
+ * SilcBuffer buffer,
+ * void *value,
+ * void *context);
+ *
+ * DESCRIPTION
+ *
+ * Formatting function callback given with SILC_STR_FUNC type. The
+ * `buffer' is the buffer being formatted at the location where the
+ * SILC_STR_FUNC was placed in formatting. The function should call
+ * silc_buffer_senlarge before it adds the data to the buffer to make
+ * sure that it has enough space. The buffer->head points to the
+ * start of the buffer and silc_buffer_headlen() gives the length
+ * of the currently formatted data area. It is also possible to use
+ * silc_buffer_sformat with `buffer' which will enlarge the buffer if
+ * needed.
+ *
+ * The `value' is the value given to SILC_STR_FUNC that is to be formatted
+ * into the buffer. It may be NULL if the function is not formatting
+ * new data into the buffer. The `context' is caller specific context.
+ * Returns -1 on error and length of the formatted value otherwise, and
+ * 0 if nothing was formatted.
+ *
+ * This is same as SilcBufferFormatFunc except the SilcStack will be
+ * delivered. This callback must be used when SilcStack is used with
+ * formatting.
+ *
+ ***/
+typedef int (*SilcBufferSFormatFunc)(SilcStack stack, SilcBuffer buffer,
+ void *value, void *context);
+
+/****f* silcutil/SilcBufferFormatAPI/SilcBufferUnformatFunc
+ *
+ * SYNOPSIS
+ *
+ * typedef int (*SilcBufferUnformatFunc)(SilcBuffer buffer,
+ * void **value,
+ * void *context);
+ *
+ * DESCRIPTION
+ *
+ * Unformatting function callback given with SILC_STR_FUNC type. The
+ * `buffer' is the buffer being unformatted and is at the location where
+ * the SILC_STR_FUNC was placed in unformatting. The function should
+ * check there is enough data in the `buffer' before trying to decode
+ * from it.
+ *
+ * If this function unformats anything from the buffer its value is to
+ * be returned to the `value' pointer. The implementation should itself
+ * decide whether the unformatted value is allocated or not. If this
+ * function does not unformat anything, nothing is returned to `value'
+ *
+ * The `context' is caller specific context. Returns -1 on error, and
+ * length of the unformatted value otherwise, and 0 if nothing was
+ * unformatted.
+ *
+ ***/
+typedef int (*SilcBufferUnformatFunc)(SilcBuffer buffer, void **value,
+ void *context);
+
+/****f* silcutil/SilcBufferFormatAPI/SilcBufferSUnformatFunc
+ *
+ * SYNOPSIS
+ *
+ * typedef int (*SilcBufferSUnformatFunc)(SilcStack stack,
+ * SilcBuffer buffer,
+ * void **value,
+ * void *context);
+ *
+ * DESCRIPTION
+ *
+ * Unformatting function callback given with SILC_STR_FUNC type. The
+ * `buffer' is the buffer being unformatted and is at the location where
+ * the SILC_STR_FUNC was placed in unformatting. The function should
+ * check there is enough data in the `buffer' before trying to decode
+ * from it.
+ *
+ * If this function unformats anything from the buffer its value is to
+ * be returned to the `value' pointer. The implementation should itself
+ * decide whether the unformatted value is allocated or not. If this
+ * function does not unformat anything, nothing is returned to `value'
+ *
+ * The `context' is caller specific context. Returns -1 on error, and
+ * length of the unformatted value otherwise, and 0 if nothing was
+ * unformatted.
+ *
+ * This is same as SilcBufferUnformatFunc except the SilcStack will be
+ * delivered. This callback must be used when SilcStack is used with
+ * unformatting.
+ *
+ ***/
+typedef int (*SilcBufferSUnformatFunc)(SilcStack stack, SilcBuffer buffer,
+ void **value, void *context);
+