Ubuntu file types

To create a new file type on Gnome/Nautilus, eg., for tsclient configuration files (*.rdp), go or create the directory:

~/.local/share/mime/packages

Create a new file tsclient.xml:

<?xml version="1.0" encoding="UTF-8"?>
<mime-info xmlns='http://www.freedesktop.org/standards/shared-mime-info'>
  <mime-type type="application/x-rdp">
    <comment>tsclient configuration file</comment>
    <glob pattern="*.rdp"/>
  </mime-type>
</mime-info>

Update the mime database:

update-mime-database ~/.local/share/mime