diff --git a/source/CircularQueueBuffer.hpp b/source/CircularQueueBuffer.hpp
index d4f8cef885ae40120c0fe8999efc5df7836a6783..77dd28b860e53ec7901caf47333259554d64009a 100644
--- a/source/CircularQueueBuffer.hpp
+++ b/source/CircularQueueBuffer.hpp
@@ -9,6 +9,7 @@
  * @details This is useful in many places in the project to implement simple
  * buffers, the contents of which don't need shifting as items are removed from
  * the head. This type automatically handles index-translation.
+ * @note As this is a templated type, this is a header-only compilation unit.
  *
  * @author Joshua Saxby <Joshua2.Saxby@live.uwe.ac.uk>
  * @date 2020
diff --git a/source/ManchesterEncoder.hpp b/source/ManchesterEncoder.hpp
index d04e5b3e6270c27a94e60b5ecce8579b2d5e54bb..8c5c6cce7af3c1186ad440b8e4e1597d75b0580f 100644
--- a/source/ManchesterEncoder.hpp
+++ b/source/ManchesterEncoder.hpp
@@ -6,11 +6,12 @@
  *
  * @brief A simple class that performs Manchester Encoding of input bytes
  *
- * @details TODO ADD DESCRIPTION HERE
- *
- * @todo Move the implementation code out of this header and into a
- * corresponding .cpp file. I can't do this right now as I currently don't know
- * how to make Yotta build multiple objects...
+ * @details Bytes are sent into the encoder with the input() method and line
+ * states to set (HI/LO) are returned with the get_next_state() method.
+ * Bytes are encoded in big-endian order and the Manchester Encoding version
+ * conforms to that used in IEEE 802.3, that is, the clock cycles HI-LOW and
+ * output is Clock XOR Data. Thus, a HI-LOW transition indicates binary zero,
+ * whereas a LOW-HI transition indicates binary one.
  *
  * @author Joshua Saxby <Joshua2.Saxby@live.uwe.ac.uk>
  * @date 2020
diff --git a/source/MorseDecoder.hpp b/source/MorseDecoder.hpp
index 9769e79cc28d5a3238bbc4a4a19dbaa1564c412b..d98764d0f336daea07c17fe6712b40238b1b78b7 100644
--- a/source/MorseDecoder.hpp
+++ b/source/MorseDecoder.hpp
@@ -40,6 +40,8 @@ namespace com_saxbophone {
         /**
          * @brief Constructor
          * @param unit_duration the duration of one Morse Code 'unit' in ms
+         * @todo Consider converting to constexpr to allow const derivation of
+         * unit durations at compile-time.
          */
         MorseDecoder(unsigned long unit_duration)
             // pre-compute the duration of symbols in ms
diff --git a/source/MorseSymbol.hpp b/source/MorseSymbol.hpp
index c1c6fdab9eb46cd40cc1919f080b2ad916e98b49..12f8786373e410443f5f286fba288098c3a7c79c 100644
--- a/source/MorseSymbol.hpp
+++ b/source/MorseSymbol.hpp
@@ -6,12 +6,6 @@
  *
  * @brief A simple data type used to represent the symbols of Morse Code
  *
- * @details TODO ADD DESCRIPTION HERE
- *
- * @todo Move the implementation code out of this header and into a
- * corresponding .cpp file. I can't do this right now as I currently don't know
- * how to make Yotta build multiple objects...
- *
  * @author Joshua Saxby <Joshua2.Saxby@live.uwe.ac.uk>
  * @date 2020
  *
@@ -25,7 +19,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-
 // SAXBOPHONE.COM is my domain, so I'm using the reverse form as my namespace
 namespace com_saxbophone {
     /**