diff --git a/src/l2cap.c b/src/l2cap.c
index 8063b32b4..0e0ba9810 100644
--- a/src/l2cap.c
+++ b/src/l2cap.c
@@ -794,10 +794,12 @@ uint8_t *l2cap_get_outgoing_buffer(void){
     return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes
 }
 
+// only for L2CAP Basic Channels
 int l2cap_reserve_packet_buffer(void){
     return hci_reserve_packet_buffer();
 }
 
+// only for L2CAP Basic Channels
 void l2cap_release_packet_buffer(void){
     hci_release_packet_buffer();
 }
@@ -1097,6 +1099,7 @@ static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_
 }
 
 // assumption - only on Classic connections
+// cannot be used for L2CAP ERTM
 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){
     
     if (!hci_is_packet_buffer_reserved()){
diff --git a/src/l2cap.h b/src/l2cap.h
index ed4891aae..527f76506 100644
--- a/src/l2cap.h
+++ b/src/l2cap.h
@@ -523,21 +523,25 @@ void l2cap_request_can_send_now_event(uint16_t local_cid);
 
 /** 
  * @brief Reserve outgoing buffer
+ * @note Only for L2CAP Basic Mode Channels
  */
 int  l2cap_reserve_packet_buffer(void);
 
 /** 
  * @brief Get outgoing buffer and prepare data.
+ * @note Only for L2CAP Basic Mode Channels
  */
 uint8_t *l2cap_get_outgoing_buffer(void);
 
 /** 
  * @brief Send L2CAP packet prepared in outgoing buffer to channel
+ * @note Only for L2CAP Basic Mode Channels
  */
 int l2cap_send_prepared(uint16_t local_cid, uint16_t len);
 
 /** 
  * @brief Release outgoing buffer (only needed if l2cap_send_prepared is not called)
+ * @note Only for L2CAP Basic Mode Channels
  */
 void l2cap_release_packet_buffer(void);