How to disable directory browsing on Apache
If it is not in a directory on the server found the default file (for example. index.html) may occur according to the server settings different situations. The default and potentially dangerous can display the contents of a directory, which displays links to file inside the directory.

Deactivation for the entire server make by removing the options Options Indexes in the configuration file /etc/apache2/apache2.conf
<Directory /var/www/>
Options Indexes FollowSymLinks
</Directory>
If you would like opt in only some of directory. Create a new configuration file block that links to the directory (Docs)
<Directory /var/www/adresar/Docs>
Options Indexes FollowSymLinks
</Directory>
Or
In the desired directory (/var/www/adresar/Docs)
edit the
contents of a file .htaccess and add the
following code:
Options Indexes
Links : Apache Module mod_autoindex, Option Directive.