diff --git a/doc/comment_action.md b/doc/comment_action.md
index ac1d0a2..d56bd7e 100644
--- a/doc/comment_action.md
+++ b/doc/comment_action.md
@@ -1,9 +1,10 @@
 About Action in Issue Comment
 ========
 After the issue creation at GitBucket, users can add comments or close it.
-The details are saved at ```ISSUE_COMMENT``` table.
+The details are saved at `ISSUE_COMMENT` table.
 
-To determine if it was any operation, you see the ```ACTION``` column.
+To determine if it was any operation, you see the `ACTION` column.
+And in the case of some actions, `CONTENT` column value contains additional information.
 
 |ACTION         |CONTENT          |
 |---------------|-----------------|
@@ -28,28 +29,28 @@
 ### close, reopen
 
 These values are saved when users have reopened or closed the issue.
-At the same time, store the fixed value(i.e. "Close" or "Reopen") to the ```CONTENT``` column.
+At the same time, store the fixed value(i.e. "Close" or "Reopen") to the `CONTENT` column.
 Therefore, this comment is not displayed, and not counted as a comment.
 
 ### commit
 
-This value is saved when users have pushed including the ```#issueId``` to the commit message.
-At the same time, store it to the ```CONTENT``` column with its commit id.
+This value is saved when users have pushed including the `#issueId` to the commit message.
+At the same time, store it to the `CONTENT` column with its commit id.
 This comment is displayed. But it can not be edited by all users, and also not counted as a comment.
 
 ### merge
 
 This value is saved when users have merged the pull request.
-At the same time, store the message to the ```CONTENT``` column.
+At the same time, store the message to the `CONTENT` column.
 This comment is displayed. But it can not be edited by all users, and also not counted as a comment.
 
 ### delete_branch
 
 This value is saved when users have deleted the branch. Users can delete branch after merging pull request which is requested from the same repository.
-At the same time, store it to the ```CONTENT``` column with the deleted branch name.
+At the same time, store it to the `CONTENT` column with the deleted branch name.
 Therefore, this comment is not displayed, and not counted as a comment.
 
-##### refer
+### refer
 
-This value is saved when other issue or issue comment contains reference to the issue like ```#issueId```.
-At the same time, store id and title of the referrer issue as ```id:title```.
+This value is saved when other issue or issue comment contains reference to the issue like `#issueId`.
+At the same time, store id and title of the referrer issue as `id:title`.