diff --git a/os/hal/platforms/STM32/adc_lld.h b/os/hal/platforms/STM32/adc_lld.h
index b63466250..2a91c9b4d 100644
--- a/os/hal/platforms/STM32/adc_lld.h
+++ b/os/hal/platforms/STM32/adc_lld.h
@@ -126,6 +126,9 @@ typedef void (*adccallback_t)(adcsample_t *buffer, size_t n);
  * @brief   Conversion group configuration structure.
  * @details This implementation-dependent structure describes a conversion
  *          operation.
+ * @note    The use of this configuration structure requires knowledge of
+ *          STM32 ADC cell registers interface, please refer to the STM32
+ *          reference manual for details.
  */
 typedef struct {
   /**
diff --git a/todo.txt b/todo.txt
index 6343e00fa..6aa80a4fd 100644
--- a/todo.txt
+++ b/todo.txt
@@ -12,14 +12,11 @@ Within 2.1.x (hopefully)
                 on top, support data words greater than 8 bits, callback for
                 "last byte transmitted (RS485)", simple implementation,
                 verifiable.
+* Rework STM32 drivers to use friendly IRQ names and centralized DMA macros.
 X Resist doing more changes and optimizations in the kernel, fixes only.
-X Rework STM32 drivers to use friendly IRQ names and centralized DMA macros.
 X File System infrastructure.
 X General HAL improvements.
-- Add a *very simple* ADC API for simgle one shot sampling (implement it as
-  an injected conversion on the STM32).
-- Evaluate if reimplement the SPI/CAN drivers to be callback-based like the
-  ADC, PWM and UART drivers, the current API could be rebuilt on top.
+- I2C device driver class support.
 - MAC driver for STM32F105/STM32F107 (hardware missing).
 - Device drivers for STM8 (SPI, ADC, PWM, bring it on par with STM32).
 - Support for more compilers (ARMCMx only initially).
@@ -30,7 +27,10 @@ Later but within 2.x.x
 - Merge the Coldfire branch in mainline.
 - Merge the H8S branch in mainline.
 - Debug-related features and tools.
-- I2C device driver class support.
+- Evaluate if reimplement the SPI/CAN drivers to be callback-based like the
+  ADC, PWM and UART drivers, the current API could be rebuilt on top.
+- Add a *very simple* ADC API for single one shot sampling (implement it as
+  an injected conversion on the STM32).
 - USB device driver class support.
 - MAC driver revision in order to support copy-less operations, this will
   require changes to lwIP or a new TCP/IP stack however.