This is just to understand some internals of ISPConfig. I have noticed that ISPConfig creates an user for each site, called webX, which belongs to a group called clientY. The folder web, which contains all the accessible data of a site, belongs to webX. The user that nginx (this is the web server software used in my case) uses to serve the sites is www-data. The user www-data belong to all clientY groups. So, first question: is all the above correct? And second: Say I have a wordpress installation on the web folder of webX site. Any file has 644 permissions, and any dir has 755 permissions. So, www-data have 4=r-- permissions on any file, and 5=r-x permissions on any dir. In such configuration, I am allowed to, i.e., install a pluigin in wordpress. How can www-data write to the plugin folder to install the plugin? (cause I checked it is able to). Thanks a lot.