diff --git a/sys/include/net/sock.h b/sys/include/net/sock.h
index 339a89a132..ebf9481c06 100644
--- a/sys/include/net/sock.h
+++ b/sys/include/net/sock.h
@@ -245,19 +245,6 @@ struct _sock_tl_ep {
     uint16_t port;          /**< transport layer port (in host byte order) */
 };
 
-/**
- * @brief   Releases the stack-internal buffer space provided by the
- *          `sock_*_recv_buf()` functions.
- *
- * @see
- *  - @ref sock_dtls_recv_buf()
- *  - @ref sock_ip_recv_buf()
- *  - @ref sock_udp_recv_buf()
- *
- * @param[in] buf_ctx   Stack-internal buffer context to release.
- */
-void sock_recv_buf_free(void *buf_ctx);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/sys/include/net/sock/dtls.h b/sys/include/net/sock/dtls.h
index 54b098d1df..8ed6e50d21 100644
--- a/sys/include/net/sock/dtls.h
+++ b/sys/include/net/sock/dtls.h
@@ -615,9 +615,11 @@ ssize_t sock_dtls_recv(sock_dtls_t *sock, sock_dtls_session_t *remote,
  *                      Cannot be NULL.
  * @param[out] data     Pointer to a stack-internal buffer space containing the
  *                      received data.
- * @param[out] buf_ctx  Stack-internal buffer context. Must be used to release
- *                      the buffer space using @ref sock_recv_buf_free() after
- *                      the data in @p data was handled.
+ * @param[in,out] buf_ctx   Stack-internal buffer context. If it points to a
+ *                      `NULL` pointer, the stack returns a new buffer space for
+ *                      a new packet. If it does not point to a `NULL` pointer,
+ *                      an existing context is assumed to get a next segment in
+ *                      a buffer.
  * @param[in] timeout   Receive timeout in microseconds.
  *                      If 0 and no data is available, the function returns
  *                      immediately.
@@ -626,7 +628,13 @@ ssize_t sock_dtls_recv(sock_dtls_t *sock, sock_dtls_session_t *remote,
  *
  * @note Function may block if data is not available and @p timeout != 0
  *
- * @return The number of bytes received on success
+ * @note    Function blocks if no packet is currently waiting.
+ *
+ * @return  The number of bytes received on success. May not be the complete
+ *          payload. Continue calling with the returned @p buf_ctx to get more
+ *          buffers until result is 0 or an error.
+ * @return  0, if no received data is available, but everything is in order.
+ *          If @p buf_ctx was provided, it was released.
  * @return  -EADDRNOTAVAIL, if the local endpoint of @p sock is not set.
  * @return  -EAGAIN, if @p timeout is `0` and no data is available.
  * @return  -EINVAL, if @p remote is invalid or @p sock is not properly
diff --git a/sys/include/net/sock/ip.h b/sys/include/net/sock/ip.h
index d19139ec0a..0b3deb9bdc 100644
--- a/sys/include/net/sock/ip.h
+++ b/sys/include/net/sock/ip.h
@@ -435,9 +435,11 @@ ssize_t sock_ip_recv(sock_ip_t *sock, void *data, size_t max_len,
  * @param[in] sock      A raw IPv4/IPv6 sock object.
  * @param[out] data     Pointer to a stack-internal buffer space containing the
  *                      received data.
- * @param[out] buf_ctx  Stack-internal buffer context. Must be used to release
- *                      the buffer space using @ref sock_recv_buf_free() after
- *                      the data in @p data was handled.
+ * @param[in,out] buf_ctx  Stack-internal buffer context. If it points to a
+ *                      `NULL` pointer, the stack returns a new buffer space
+ *                      for a new packet. If it does not point to a `NULL`
+ *                      pointer, an existing context is assumed to get a next
+ *                      segment in a buffer.
  * @param[in] timeout   Timeout for receive in microseconds.
  *                      If 0 and no data is available, the function returns
  *                      immediately.
@@ -448,8 +450,11 @@ ssize_t sock_ip_recv(sock_ip_t *sock, void *data, size_t max_len,
  *
  * @note    Function blocks if no packet is currently waiting.
  *
- * @return  The number of bytes received on success.
+ * @return  The number of bytes received on success. May not be the complete
+ *          payload. Continue calling with the returned `buf_ctx` to get more
+ *          buffers until result is 0 or an error.
  * @return  0, if no received data is available, but everything is in order.
+ *          If @p buf_ctx was provided, it was released.
  * @return  -EADDRNOTAVAIL, if local of @p sock is not given.
  * @return  -EAGAIN, if @p timeout is `0` and no data is available.
  * @return  -EINVAL, if @p remote is invalid or @p sock is not properly
diff --git a/sys/include/net/sock/udp.h b/sys/include/net/sock/udp.h
index f0cadad467..1fe7124c03 100644
--- a/sys/include/net/sock/udp.h
+++ b/sys/include/net/sock/udp.h
@@ -422,9 +422,11 @@ ssize_t sock_udp_recv(sock_udp_t *sock, void *data, size_t max_len,
  * @param[in] sock      A UDP sock object.
  * @param[out] data     Pointer to a stack-internal buffer space containing the
  *                      received data.
- * @param[out] buf_ctx  Stack-internal buffer context. Must be used to release
- *                      the buffer space using @ref sock_recv_buf_free() after
- *                      the data in @p data was handled.
+ * @param[in,out] buf_ctx  Stack-internal buffer context. If it points to a
+ *                      `NULL` pointer, the stack returns a new buffer space
+ *                      for a new packet. If it does not point to a `NULL`
+ *                      pointer, an existing context is assumed to get a next
+ *                      segment in a buffer.
  * @param[in] timeout   Timeout for receive in microseconds.
  *                      If 0 and no data is available, the function returns
  *                      immediately.
@@ -435,8 +437,11 @@ ssize_t sock_udp_recv(sock_udp_t *sock, void *data, size_t max_len,
  *
  * @note    Function blocks if no packet is currently waiting.
  *
- * @return  The number of bytes received on success.
+ * @return  The number of bytes received on success. May not be the complete
+ *          payload. Continue calling with the returned `buf_ctx` to get more
+ *          buffers until result is 0 or an error.
  * @return  0, if no received data is available, but everything is in order.
+ *          If @p buf_ctx was provided, it was released.
  * @return  -EADDRNOTAVAIL, if local of @p sock is not given.
  * @return  -EAGAIN, if @p timeout is `0` and no data is available.
  * @return  -EINVAL, if @p remote is invalid or @p sock is not properly