4 files changed, 13 insertions, 0 deletions

diff --git a/docs/feature_split_keyboard.md b/docs/feature_split_keyboard.md
index b23411420..c285e353d 100644
--- a/docs/feature_split_keyboard.md
+++ b/docs/feature_split_keyboard.md
@@ -181,6 +181,16 @@ If you're having issues with serial communication, you can change this value, as
 * **`4`**: about 26kbps
 * **`5`**: about 20kbps
 
+```c
+#define SPLIT_MODS_ENABLE
+```
+
+This enables transmitting modifier state (normal, weak and oneshot) to the non
+primary side of the split keyboard.  This adds a few bytes of data to the split
+communication protocol and may impact the matrix scan speed when enabled.
+The purpose of this feature is to support cosmetic use of modifer state (e.g.
+displaying status on an OLED screen).
+
 ###  Hardware Configuration Options
 
 There are some settings that you may need to configure, based on how the hardware is set up. 
diff --git a/docs/ja/proton_c_conversion.md b/docs/ja/proton_c_conversion.md
index 6e4f7dcb6..e7c07413c 100644
--- a/docs/ja/proton_c_conversion.md
+++ b/docs/ja/proton_c_conversion.md
@@ -51,6 +51,7 @@ Proton C には1つのオンボード LED(C13)しかなく、デフォルトで�
 
 ```
 MCU = STM32F303
+BOARD = QMK_PROTON_C
 ```
 
 次の変数が存在する場合は削除します。
diff --git a/docs/proton_c_conversion.md b/docs/proton_c_conversion.md
index 1b5e496e7..47511e1b1 100644
--- a/docs/proton_c_conversion.md
+++ b/docs/proton_c_conversion.md
@@ -44,6 +44,7 @@ To use the Proton C natively, without having to specify `CTPC=yes`, you need to
 
 ```
 MCU = STM32F303
+BOARD = QMK_PROTON_C
 ```
 
 Remove these variables if they exist:
diff --git a/docs/serial_driver.md b/docs/serial_driver.md
index bc376b6dd..c98f4c117 100644
--- a/docs/serial_driver.md
+++ b/docs/serial_driver.md
@@ -60,6 +60,7 @@ Configure the hardware via your config.h:
                                    //  5: about 19200 baud
 #define SERIAL_USART_DRIVER SD1 // USART driver of TX pin. default: SD1
 #define SERIAL_USART_TX_PAL_MODE 7 // Pin "alternate function", see the respective datasheet for the appropriate values for your MCU. default: 7
+#define SERIAL_USART_TIMEOUT 100 // USART driver timeout. default 100
 ```
 
 You must also enable the ChibiOS `SERIAL` feature: