The rich text box is a box that allows you to see the text that you type in the browser. This can be used to create websites or to simply read the content. The bug is that if you have a textbox and you edit it when you save the page, it doesn't save the change. It saves the original value. You can check https://rubygarage.org/services/web-application-testing to get knowledge about web application testing. If you use the text-align: center; property on your rich text box, it will not work properly when you use the rich text box in an article or other content.