diff --git a/README.md b/README.md
index 7c61827..0145f1c 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-keybrd library for creating custom-keyboard firmware
+keybrd library for creating keyboard firmware
 ====================================================
 keybrd library is an open source library for creating custom-keyboard firmware.
 The resulting keyboard firmware is compatible with standard USB keyboard drivers.
@@ -24,7 +24,7 @@ The keybrd library has been tested on the Teensy 2.0 microcontroller, MCP23018 I
 Example minimal keybrd sketch
 -----------------------------
 <!-- todo after teensy LC bb, copy and remove annotations from keybrd_single-layer_2_annotated.ino -->
-Here is a [minimal keybrd sketch](blob/master/tutorials/keybrd_2_single-layer_annotated/keybrd_2_single-layer_annotated.ino).
+Here is a [minimal keybrd sketch](tutorials/keybrd_2_single-layer_annotated/keybrd_2_single-layer_annotated.ino).
 The sketch has about 50 lines of code and runs on a 4-key keyboard.
 It runs on a breadboard with rows, columns, and diodes just like the big keyboards.
 The sketch is small because the keybrd library takes care of the low-level details.
@@ -35,16 +35,16 @@ The keybrd tutorials 2, 3, and 4 show how to create custom keybrd firmware.
 Example complex keybrd sketch
 -----------------------------
 The keybrd_DH emulates the DataHand keyboard.
-It has 72 keys, 4 layers, a sub-layers, 2 matrices, and is loaded with features.
-The keybrd_DH and its instantiation files, contain about 800 lines of code.
+It has 72 keys, 4 layers, a sub-layer, 2 matrices, and many features.
+The keybrd_DH and its instantiation files contain about 800 lines of code.
 
-    [mainSketch.ino](../keybrd_DH/blob/master/examples/keybrd_DH/mainSketch.cpp)
-    [instantiations_ports.h](../keybrd_DH/tree/master/src/instantiations_ports.h)
-    [instantiations_LEDs.h](../keybrd_DH/tree/master/src/instantiations_LEDs.h)
-    [instantiations_codes.h](../keybrd_DH/tree/master/src/instantiations_codes.h)
-    [instantiations_matrix.h](../keybrd_DH/tree/master/src/instantiations_matrix.h)
+[mainSketch.ino](../keybrd_DH/blob/master/examples/keybrd_DH/mainSketch.cpp)<br>
+[instantiations_ports.h](../keybrd_DH/tree/master/src/instantiations_ports.h)<br>
+[instantiations_LEDs.h](../keybrd_DH/tree/master/src/instantiations_LEDs.h)<br>
+[instantiations_codes.h](../keybrd_DH/tree/master/src/instantiations_codes.h)<br>
+[instantiations_matrix.h](../keybrd_DH/tree/master/src/instantiations_matrix.h)
 
 Support
 -------
-[Guides](tree/master/doc) and [tutorials](/tree/master/tutorials) are provided.
+[Guides](doc) and [tutorials](tutorials) are provided.
 Please ask a questions in [issues](https://github.com/wolfv6/Keybrd/issues) if something is not clear.
diff --git a/doc/keybrd_library_developer_guide.md b/doc/keybrd_library_developer_guide.md
index 5bf9191..34dcf7d 100644
--- a/doc/keybrd_library_developer_guide.md
+++ b/doc/keybrd_library_developer_guide.md
@@ -136,7 +136,7 @@ Following the style guide makes it easier for the next programmer to understand
 * Code should be self-documenting.
   The only comments should be things that may need clarification.
   A simple function with a good name needs no comment.
-  <-- http://stackoverflow.com/questions/2198241/best-practice-for-c-function-commenting !-->
+  <--! http://stackoverflow.com/questions/2198241/best-practice-for-c-function-commenting -->
 * Code is automatically formated before being pushed to the keybrd repository
   The options file doc/astyle_cpp specifies the format:
     * Allman style indentation
diff --git a/doc/keybrd_library_user_guide.md b/doc/keybrd_library_user_guide.md
index 7308d3c..2b24692 100644
--- a/doc/keybrd_library_user_guide.md
+++ b/doc/keybrd_library_user_guide.md
@@ -65,18 +65,18 @@ For Linux:
 4. Launch Arduino IDE from /opt/arduino-1.x.x/arduino
 
 ### Download and unpack keybrd-master.zip into your Arduino directory
-<-- todo update after testing Arduino library manager
+<--! todo update after testing Arduino library manager
 link from tutorial 7 ## Publishing
     https://www.arduino.cc/en/Guide/Libraries
      > Installing Additional Arduino Libraries
      > Using the Library Manager
- !-->
+ -->
 Down load keybrd-master.zip from the [Download ZIP](https://github.com/wolfv6/keybrd) button.
 
 Unpack keybrd-master.zip into your Arduino directory on your system (default location is ~/Documents/Arduino/).
 
 ### keybrd library and keybrd extension libraries
-<-- todo update after testing Arduino library manager !-->
+<--! todo update after testing Arduino library manager -->
 
 The keybrd library contains the foundation classes for creating a keyboard firmware.
 For emphasis, it is referred to as the "core keybrd library".
@@ -144,9 +144,9 @@ The first two fields are mandatory, the remaining fields are optional.
 
 ## Diode orientation
 The physical martix rows and columns on a keyboard can be in any direction or shape.
-[diode](https://en.wikipedia.org/wiki/Diode) orientation is specified in [Matrix.h](todo)
+[diode](https://en.wikipedia.org/wiki/Diode) orientation is specified in [Matrix.h](https://github.com/wolfv6/keybrd/blob/master/src/Matrix.h)
 
-![Diode](../tutorials/images/120px-Diode_pinout_en_fr.svg.png)
+[Diode](../tutorials/images/120px-Diode_pinout_en_fr.svg.png)
 
 Diagram is of typical through-the-hole diode in same alignment as diode symbol.
 Cross bar and band depict the cathode.