diff --git a/docs/DeveloperGuide.md b/docs/DeveloperGuide.md
index 03092eb96aa..bd475fddc38 100644
--- a/docs/DeveloperGuide.md
+++ b/docs/DeveloperGuide.md
@@ -329,13 +329,13 @@ Priorities: Essential (needed for basic functionality) - `Essential`, Typical (c
 
 * 3b. The unnecessary fields given.
 
-    * 3a1. HRConnect shows an error message.
+    * 3b1. HRConnect shows an error message.
 
       Use case resumes at step 2.
 
 * 3c. The contact details have been added before.
 
-    * 3b1. HRConnect shows an error message.
+    * 3c1. HRConnect shows an error message.
 
       Use case resumes at step 2.
 
@@ -417,14 +417,14 @@ Priorities: Essential (needed for basic functionality) - `Essential`, Typical (c
       Use case resumes at step 2.
 
 
-**Use case: Edit a person**
+**Use case: Edit an applicant**
 
 **MSS**
 
 1.  User requests to list of contacts
 2.  HRConnect shows a list of contacts
-3.  User requests to edit a specific person's details in the list
-4.  HRConnect edits the details belonging to the person
+3.  User requests to edit a specific applicant's details in the list
+4.  HRConnect edits the details belonging to the applicant
 
     Use case ends.
 
@@ -434,7 +434,7 @@ Priorities: Essential (needed for basic functionality) - `Essential`, Typical (c
 
   Use case ends.
 
-* 3a. The given index of the person is invalid.
+* 3a. The given index of the applicant is invalid.
 
     * 3a1. HRConnect shows an error message.
 
@@ -445,6 +445,19 @@ Priorities: Essential (needed for basic functionality) - `Essential`, Typical (c
     * 3b1. HRConnect shows an error message.
 
       Use case resumes at step 2.
+      
+* 3c. Newly applied changes were the same as before.
+
+    * 3c1. HRConnect shows an error message.
+
+      Use case resumes at step 2.
+
+* 3d. The applicant already exists in HRConnect.
+
+    * 3d1. HRConnect shows an error message.
+
+      Use case resumes at step 2.
+      
 
 **Use case: Export contacts**
 
@@ -528,7 +541,7 @@ Priorities: Essential (needed for basic functionality) - `Essential`, Typical (c
 **MSS**
 
 1.  User requests to list persons
-2.  AddressBook shows a list of persons
+2.  HRConnect shows a list of persons
 
     Use case ends.