A staging site (during development phase) should not be visible for security reasons but also for SEO issues. Indeed, making the staging site 'invisible' will prevent the creation of duplicate content (from the existing content) and will prevent to create value on a staging domain that has no indexing objective as it does not aim to be visible for either users nor search engines.
Plan to restrict access to your staging site by IP addresses - for a limited number of IPs. Just place the following lines in your .htaccess file or in the virtual host configuration of your dev site.
The IP address of the Acquisit office is: 94.202.255.10
If IPs are not fixed, provide a restriction by password - by placing the following lines in your .htaccess file:
=>> Use a Basic or Digest authentication method
It is important to create a staging site that will be as up-to-date as possible in order not to have any discrepancies between the recommendations established on the different versions and the final release.
Warning
Blocking by robots.txt or with a noindex instruction are not good solutions. We strongly recommend that you do not use these methods.