diff --git a/Doc/Sda1/prerequisites.xml b/Doc/Sda1/prerequisites.xml
index 8e4ef29d504ba15c8b4c051f30ee38740bfbfc62..c279caa01772913bcb3ac5edecf2a5f8418923b3 100644
--- a/Doc/Sda1/prerequisites.xml
+++ b/Doc/Sda1/prerequisites.xml
@@ -326,9 +326,20 @@ Enter password:
 
 ... messages omitted for brevity ...
 
-mysql&gt; <emphasis role="bold">create database hdm;</emphasis>
+mysql&gt; <emphasis role="bold">create database hdm CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;</emphasis> <co
+          linkends="sda1_prereq_screen_mysqlCreateDatabase-1"
+          xml:id="sda1_prereq_screen_mysqlCreateDatabase-1-co"/>
 Query OK, 1 row affected (0.00 sec)</screen>
 
+      <calloutlist>
+        <callout arearefs="sda1_prereq_screen_mysqlCreateDatabase-1-co"
+                 xml:id="sda1_prereq_screen_mysqlCreateDatabase-1">
+          <para>This parameter setting mitigates key limitations, <link
+          xlink:href="https://stackoverflow.com/questions/20014106/how-to-create-this-table-1071-specified-key-was-too-long-max-key-length-is/42497309#answer-49233800">see
+          detailed explanation</link>.</para>
+        </callout>
+      </calloutlist>
+
       <para>Following <uri
       xlink:href="https://dev.mysql.com/doc/refman/5.5/en/adding-users.html">https://dev.mysql.com/doc/refman/5.5/en/adding-users.html</uri>
       we add <code>hdmuser</code> as a new user and grant full access to the