diff --git a/documentation/demo-system-structure.md b/documentation/demo-system-structure.md
index d6bd58a..b3b6d8e 100644
--- a/documentation/demo-system-structure.md
+++ b/documentation/demo-system-structure.md
@@ -17,7 +17,7 @@ The ${demoextras} folder is:
 
     /home/ipol/ipolDevel/shared_folder/demoExtras/333330010008
 
-and its content is the unpacked demoxetra archive upploaded in the control
+and its content is the unpacked demoxetra archive uploaded in the control
 panel, i.e.:
 
     run.py
@@ -40,8 +40,8 @@ and it contains
     unpacked
 
 That is, the downloaded input "input_0", the parameters, stdout and stderr.
-This is the place where the "algo_infot.txt" has to be created (in ${bin} for
-example, I won't work). The rest has been created by my code.
+This is the place where the "algo_info.txt" has to be created (in ${bin} for
+example). The rest has been created by my code.
 
 Variables accessible from the ddl:
 
@@ -72,7 +72,7 @@ However, the virtualenv is not created yet and the $virtualenv variable is not
 set.
 
 If the "execution successful" appears but the "run" animated icon is still
-thre, it means that there is an issue somewhere when interpreting the ddl.
+there, it means that there is an issue somewhere when interpreting the ddl.
 Start by verifying your algo_info.txt if you have one...
 
 --> Email to IPOL team...(?) DDL errors should make the demo fail and give an
diff --git a/documentation/hidden_features.md b/documentation/hidden_features.md
index b377b15..256eaf8 100644
--- a/documentation/hidden_features.md
+++ b/documentation/hidden_features.md
@@ -6,12 +6,14 @@ its content after warning that the demo failed.
 However your script must exit successfully (exit code 0) for this message to be
 displayed, so you're in charge of catching the errors.
 
-This allows to catch common situation in wich your demo will fail and give the
+This allows to catch common situation in which your demo will fail and give the
 user appropriate feedback.
 
 If you have
 
-    set -e
+```bash
+set -e
+```
 
 at the beginning of your script, remove it.
 Then catch the error, create the file "demo_failure.txt" with your message,
@@ -19,11 +21,12 @@ then exit your script with exit code 0.
 
 Example:
 
-    ### unzip the given archive. IPOL demo system will have renamed it input_0
-    ### option -q makes it quiet.
-    unzip -q input_0
-    if [ $? != 0 ]; then # input_0 is not a zip file
-      echo "Failed to unzip the uploaded file." > demo_failure.txt
-      exit 0
-    fi
-
+```bash
+### unzip the given archive. IPOL demo system will have renamed it input_0
+### option -q makes it quiet.
+unzip -q input_0
+if [ $? != 0 ]; then # input_0 is not a zip file
+  echo "Failed to unzip the uploaded file." > demo_failure.txt
+  exit 0
+fi
+```
diff --git a/documentation/official_documentation.md b/documentation/official_documentation.md
index 79f35c0..8e6c057 100644
--- a/documentation/official_documentation.md
+++ b/documentation/official_documentation.md
@@ -6,7 +6,7 @@ and the sources at:
 
     https://github.com/mcolom/ipolDevel/tree/devel/doc/ddl
 
-The forum adress is:
+The forum address is:
 
-    https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!forum/ipol-demo-editing
+    https://groups.google.com/forum/#!forum/ipol-demo-editing
 
diff --git a/documentation/undocumented_ddl.md b/documentation/undocumented_ddl.md
index 8a281b2..fbc2aba 100644
--- a/documentation/undocumented_ddl.md
+++ b/documentation/undocumented_ddl.md
@@ -86,9 +86,11 @@ The params section
 
 ### The "checkbox" type
 
-To se the default value to "false" (unchecked), use
+To set the default value to "false" (unchecked), use
 
-    "default_value": ""
+```json
+"default_value": ""
+```
 
 because the other false values, like "false" or "0" strangely evaluate to true.
 Removing the "default_value" attribute from the description however also makes