During the development phase of the store it is necessary to put the notice so the customers can aware about that and not to place any order. You should also block your demo site for robots to crawl so that it won’t crawl your dummy content under that domain. Magento provides the setting in admin panel to display that notice. Follow the steps to enable the demo store notice in your magento store.
Login to your Magento backend section
From the menu, go to System -> Configuration
On the left side menu panel under “General” select “Design”, click on the “HTML Head” section in the center of your browser screen to open it.
Set value to “Yes” for the field “Display Demo Store Notice”.
Finally, click on “Save Config” to save all changes.
The demo store notice will let you customer know that the store is in development phase and if they place any order through it they store owner won’t be liable to fulfill those orders.