Click on "Edit" in the tool bar at the top of page. The Visual Editor tool bar will now appear.
Place your cursor where you want the comment to be in the coding in the article and click. The cursor will remain in that position.
Then click "Insert" on the Visual Editor tool bar
Click on "More" to extend the menu.
Click on "Comment" and a panel will appear as shown to the right.
Type in your comment in the edit box.
Click "Insert" and the comment will be saved.
Then click "Save page" on Visual Editor tool to save the comment to the page.
Enter information in the "Summary" box and click "Save page."
While in the Visual Editor, the comment will appear as a small icon in the shape of a small gray circle with a explanation mark in the middle of it. If you put your cursor over the icon the comment will appear as a tooltip.
If in Wikitext, the comment can only be seen in "Edit source."