diff --git a/docs/DeveloperGuide.md b/docs/DeveloperGuide.md
index 56cc4e4f833..c93c2ac55b6 100644
--- a/docs/DeveloperGuide.md
+++ b/docs/DeveloperGuide.md
@@ -588,12 +588,29 @@ testers are expected to do more *exploratory* testing.
    1. Test case: undo immediately after starting the application (with no operations performed)
       Expected: No undo operation is performed. An error message appears in the status message, indicating there is no action to undo.
 
+### Adding a tag
+1. Adding a tag while all tags are being shown
+
+   1. Prerequisites: There are 2 person in the list. First person on the list has tag `CS2100`, second person has tags `floortball` and `friends`. 
+
+   1. Test case: `addtag 1 t/CS2040S`<br>
+      Expected: The first person now has 2 tags `CS2100` and `CS2040S`. The tag lists are updated accordingly.
+      
+   1. Test case: `addtag 2 t/homie t/homie`
+      Expected: The second person now has 3 tags `floortball`, `friends` and `homie`. 
+      
+   1. With the following test case:
+      1. `addtag 1 t/CS2040s`
+      1. Test case: `addtag 1 t/CS2030s t/CS2040S`
+      1. Test case: `addtag 0 t/volleyball` <br>
+      1. Test case: `addtag 3 t/homie` <br>
+      1. Test case: `addtag 2` <br>
+         Expected: No new tag added. Error details shown in the status message..
+
 ### Finding a person
 
 1. Finding a person with tags
 
-    1. Prerequisites: There are contacts in the contact list. Add some if this is not the case.
-
     1. Assumption: Pick any 2 tags (or substring of the tags) present in any contact in the contact list. Call these x and y.
 
     1. Test case: `find t/x` where `x` is the substring/tag chosen<br> 
diff --git a/docs/UserGuide.md b/docs/UserGuide.md
index d6a77a40b15..4e84dfb0d39 100644
--- a/docs/UserGuide.md
+++ b/docs/UserGuide.md
@@ -96,7 +96,6 @@ Action     | Format, Examples
 **[Redo action](#redo-a-command-redo)** | `redo`
 **[List](#listing-all-persons-list)**   | `list`
 **[Help](#viewing-help-help)**   | `help` 
-
 --------------------------------------------------------------------------------------------------------------------
 ## Commands