diff --git a/sys/include/net/ng_pktbuf.h b/sys/include/net/ng_pktbuf.h
index 56d10bec106e..5a0e9f0bb6bb 100644
--- a/sys/include/net/ng_pktbuf.h
+++ b/sys/include/net/ng_pktbuf.h
@@ -65,134 +65,18 @@ extern "C" {
  *          members of the resulting ng_pktsnip_t can be very different after
  *          execution of this function depending on what parameters you use:
  *
- * * @p pkt = NULL, @p data = NULL, @p size = 0:
- *   * no assumption about transmission direction
- *   * only the ng_pktsnip_t struct will be added to the packet buffer
- *   * ng_pktsnip_t::next = NULL
- *   * ng_pktsnip_t::data = NULL
- *   * ng_pktsnip_t::size = 0
- *   * ng_pktsnip_t::type = @p type
- * * @p pkt = NULL, data = NULL, size > 0:
- *   * no assumption about transmission direction
- *   * ng_pktsnip_t struct and range of size @p size `mem` will be added to the
- *     packet buffer
- *   * ng_pktsnip_t::next = NULL
- *   * ng_pktsnip_t::data = `mem`
- *   * ng_pktsnip_t::size = @p size
- *   * ng_pktsnip_t::type = @p type
- * * @p pkt = NULL, @p data != NULL, @p size = 0:
- *   * no assumption about transmission direction
- *   * only ng_pktsnip_t struct will be added to the packet buffer, data pointer
- *     will be set to @p data regardless if it is actually in the packet buffer or
- *     not.
- *   * ng_pktsnip_t::next = NULL
- *   * ng_pktsnip_t::data = @p data
- *   * ng_pktsnip_t::size = 0
- *   * ng_pktsnip_t::type = @p type
- *   * if @p data was from outside the packet buffer you can change both
- *     ng_pktsnip_t::data and ng_pktsnip_t::size of the result, since you do
- *     not touch any data pointers from within the packet buffer. If @p data was
- *     from within the range of the packet buffer, changing these members
- *     **will create memory leaks**.
- * * @p pkt = NULL, @p data != NULL, @p size > 0:
- *   * no assumption about transmission direction
- *   * ng_pktsnip_t struct and range of size @p size `mem` will be added to the
- *     packet buffer
- *   * @p data will be copied into `mem`
- *   * ng_pktsnip_t::next = NULL
- *   * ng_pktsnip_t::data = `mem`
- *   * ng_pktsnip_t::size = @p size
- *   * ng_pktsnip_t::type = @p type
- * * @p pkt != NULL, @p data = NULL, @p size = 0:
- *   * send direction assumed
- *   * only the ng_pktsnip_t struct will be added to the packet buffer
- *   * ng_pktsnip_t::next = @p pkt
- *   * ng_pktsnip_t::data = NULL
- *   * ng_pktsnip_t::size = 0
- *   * ng_pktsnip_t::type = @p type
- * * @p pkt != NULL, @p data = NULL, @p size > 0:
- *   * send direction assumed
- *   * ng_pktsnip_t struct and range of size @p size `mem` will be added to the
- *     packet buffer
- *   * ng_pktsnip_t::next = @p pkt
- *   * ng_pktsnip_t::data = `mem`
- *   * ng_pktsnip_t::size = @p size
- *   * ng_pktsnip_t::type = @p type
- * * @p pkt != NULL, @p data != NULL, @p size = 0:
- *   * @p data is from outside the packet:
- *     * no assumption about transmission direction
- *     * only ng_pktsnip_t struct will be added to the packet buffer, data
- *       pointer will be set to @p data
- *     * ng_pktsnip_t::next = @p pkt
- *     * ng_pktsnip_t::data = @p data
- *     * ng_pktsnip_t::size = 0
- *     * ng_pktsnip_t::type = @p type
- *     * you can change both ng_pktsnip_t::data and ng_pktsnip_t::size of the
- *       result, since you do not touch any data pointers from within the
- *       packet buffer.
- *   * @p data is from within the packet and `data != pkt->data`:
- *     * send direction assumed
- *     * only ng_pktsnip_t struct will be added to the packet buffer, data
- *       pointer will be set to @p data
- *     * ng_pktsnip_t::next = NULL
- *     * ng_pktsnip_t::data = @p data
- *     * ng_pktsnip_t::size = 0
- *     * ng_pktsnip_t::type = @p type
- *     * **do not** change the ng_pktsnip_t::data and ng_pktsnip_t::size of the
- *       result. This will most likely create memory leaks.
- *   * @p data is from within the packet and `data == pkt->data`:
- *     * receive direction assumed
- *     * only ng_pktsnip_t struct `new_pktsnip` will be added to the packet
- *       buffer, data pointer will be set to @p data
- *     * ng_pktsnip_t::next of @p pkt = `new_pktsnip`
- *     * ng_pktsnip_t::data of @p pkt = @p data
- *     * ng_pktsnip_t::size of @p pkt = 0
- *     * ng_pktsnip_t::type of @p pkt = (unchanged)
- *     * ng_pktsnip_t::next of `new_pktsnip` = NULL
- *     * ng_pktsnip_t::data of `new_pktsnip` = @p data
- *     * ng_pktsnip_t::size of `new_pktsnip` = old ng_pktsnip_t::size of @p pkt
- *     * ng_pktsnip_t::type of `new_pktsnip` = @p type
- *     * **do not** change the ng_pktsnip_t::data and ng_pktsnip_t::size of the
- *       result. This will most likely create memory leaks.
- * * @p pkt = NULL, @p data != NULL, @p size > 0:
- *   * @p data is from outside the packet:
- *     * send direction assumed
- *     * ng_pktsnip_t struct and range of size @p size `mem` will be added to the
- *       packet buffer
- *     * ng_pktsnip_t::next = @p pkt
- *     * ng_pktsnip_t::data = `mem`
- *     * ng_pktsnip_t::size = @p size
- *     * ng_pktsnip_t::type = @p type
- *     * you can change both ng_pktsnip_t::data and ng_pktsnip_t::size of the
- *       result, since you do not touch any data pointers from within the
- *       packet buffer.
- *   * @p data is from within the packet and `data != pkt->data`:
- *     * send direction assumed
- *     * only ng_pktsnip_t struct will be added to the packet buffer, data
- *       pointer will be set to @p data
- *     * ng_pktsnip_t::next = @p pkt
- *     * ng_pktsnip_t::data = @p data
- *     * ng_pktsnip_t::size = @p size
- *     * ng_pktsnip_t::type = @p type
- *     * **do not** change the ng_pktsnip_t::data and ng_pktsnip_t::size of the
- *       result. This will most likely create memory leaks.
- *   * @p data is from within the packet and `data == pkt->data`:
- *     * receive direction assumed
- *     * only ng_pktsnip_t struct `new_pktsnip` will be added to the packet
- *       buffer, data pointer will be set to @p data
- *     * ng_pktsnip_t::next of @p pkt = `new_pktsnip`
- *     * ng_pktsnip_t::data of @p pkt = @p data
- *     * ng_pktsnip_t::size of @p pkt = @p size
- *     * ng_pktsnip_t::type of @p pkt = (unchanged)
- *     * ng_pktsnip_t::next of `new_pktsnip` = NULL
- *     * ng_pktsnip_t::data of `new_pktsnip` = @p data + @p size
- *     * ng_pktsnip_t::size of `new_pktsnip` = old ng_pktsnip_t::size of @p pkt - @p size
- *     * ng_pktsnip_t::type of `new_pktsnip` = @p type
- *     * **do not** change the ng_pktsnip_t::data and ng_pktsnip_t::size of the
- *       result. This will most likely create memory leaks.
- * * for the last to cases with @p data = `pkt->data` the  memory representation
- *   of a packet changes as follows (for all other cases the values of @p pkt
- *   will not be touched):
+ * * for most cases the result will be pretty straight forward and the
+ *   packet is either assumed to be in sending direction or for creation
+ *   (@p pkt == NULL) there will be made no assumtions about direction at all.
+ * * if @p pkt != NULL, @p data = `pkt->data`, @p size < `pkt->size` receiving
+ *   direction is assumed and the following values will be set:
+ *   * ng_pktsnip_t::next of result = NULL
+ *   * ng_pktsnip_t::data of result = @p data
+ *   * ng_pktsnip_t::size of result = @p size
+ *   * ng_pktsnip_t::next of @p pkt = result
+ *   * ng_pktsnip_t::data of @p pkt = @p data + @p size
+ *   * ng_pktsnip_t::size of @p pkt = old size value - @p size
+ * * graphically this can be represented as follows:
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  * Before                                    After
@@ -224,6 +108,7 @@ extern "C" {
  *
  * @return  Pointer to the packet part that represents the new ng_pktsnip_t.
  * @return  NULL, if no space is left in the packet buffer.
+ * @return  NULL, if @p pkt != NULL, @data = `pkt->data`, and @size > `pkt->data`.
  */
 ng_pktsnip_t *ng_pktbuf_add(ng_pktsnip_t *pkt, void *data, size_t size,
                             ng_nettype_t type);