diff --git a/include/stlink.h b/include/stlink.h
index db737ac..87d708e 100644
--- a/include/stlink.h
+++ b/include/stlink.h
@@ -81,11 +81,11 @@ extern "C" {
 
     enum stlink_flash_type {
         STLINK_FLASH_TYPE_UNKNOWN = 0,
-        STLINK_FLASH_TYPE_F0,
-        STLINK_FLASH_TYPE_L0,
-        STLINK_FLASH_TYPE_F4,
-        STLINK_FLASH_TYPE_L4,
-        STLINK_FLASH_TYPE_F1_XL,
+        STLINK_FLASH_TYPE_F0, /* used by f0, f1 (except f1xl),f3. */
+        STLINK_FLASH_TYPE_F1_XL, /* f0 flash with dual bank, apparently */
+        STLINK_FLASH_TYPE_F4, /* used by f2, f4, f7 */
+        STLINK_FLASH_TYPE_L0, /* l0, l1 */
+        STLINK_FLASH_TYPE_L4, /* l4, l4+ */
         STLINK_FLASH_TYPE_G0,
         STLINK_FLASH_TYPE_G4,
         STLINK_FLASH_TYPE_WB
diff --git a/src/common.c b/src/common.c
index 9694a8b..7ca017e 100644
--- a/src/common.c
+++ b/src/common.c
@@ -3238,6 +3238,7 @@ int stlink_read_option_bytes32(stlink_t *sl, uint32_t* option_byte)
         ELOG("Option bytes read is currently not supported for connected chip\n");
         return -1;
     }
+
     switch (sl->chip_id) {
         case STLINK_CHIPID_STM32_F2:
             return stlink_read_option_bytes_f2(sl, option_byte);
@@ -3289,6 +3290,7 @@ int stlink_write_option_bytes(stlink_t *sl, stm32_addr_t addr, uint8_t* base, ui
         return -1;
     }
 
+    /* filter out on chip_id, until complete flash family are handled */
     switch (sl->chip_id) {
         case STLINK_CHIPID_STM32_F2:
             return stlink_write_option_bytes_f2(sl, base, addr, len);