diff --git a/question/type/ddmarker/README.txt b/question/type/ddmarker/README.txt
index 5376a3f7786..ac6cb89b5dd 100644
--- a/question/type/ddmarker/README.txt
+++ b/question/type/ddmarker/README.txt
@@ -1,20 +1,26 @@
 A drag-and-drop question type.
-You can use markers with text labels as drag items onto rectangular, and in Moodle 2.2+ version 
+You can use markers with text labels as drag items onto rectangular, and in Moodle 2.2+ version
 circular and polygon defined drop zones on a background image.
 
 This question type requires that gapselect question type
-https://github.com/timhunt/moodle-qtype_ddimageortext/ and 
-https://github.com/timhunt/moodle-qtype_gapselect/ 
+https://github.com/timhunt/moodle-qtype_ddimageortext/ and
+https://github.com/timhunt/moodle-qtype_gapselect/
 to be installed in order to work.
 
 This question type was written by Jamie Pratt (http://jamiep.org/).
 
-This question type will be compatible with Moodle 2.1+ or 2.2+.
+This question type is compatible with Moodle 2.1+ (MOODLE_21_STABLE branch) or 2.2+ (master branch).
 
-To install using git, type this command in the root of your Moodle install :
+To install using git for a 2.2+ Moodle installation, type this command in the root of your Moodle
+install :
 
 git clone git://github.com/jamiepratt/moodle-qtype_ddmarker.git question/type/ddmarker
 
+To install using git for a 2.1+ Moodle installation, type this command in the root of your Moodle
+install :
+
+git clone  -b MOODLE_21_STABLE git://github.com/jamiepratt/moodle-qtype_ddmarker.git question/type/ddmarker
+
 Then add question/type/ddmarker to your git ignore.
 
 Alternatively, download the zip from