I use a PC with both Ubuntu and Windows 7.
I tried to install the Calibri font in Ubuntu by opening the calibri.ttf
file found under the Windows/Fonts directory using Font Viewer and clicked on the Install button.
Now I need to uninstall that font but I can't. Font Viewer shows me that the "Calibri Regular" font is installed but does not allow me to uninstall it. Font Manager does not show Calibri in the font list. Character Map does not show Calibri in the font list. Ubuntu Software Center and Synaptic don't find anything like "calibri".
There is also no calibri file under these directories:
/usr/share/fonts
/usr/local/share/fonts
~/.fonts
The font is visible to LibreOffice, Chrome, Firefox.
EDITED
I executed gedit /etc/fonts/fonts.conf
and this is part of the result:
«!-- Font directory list --»
<dir>/usr/share/fonts</dir>
<dir>/usr/local/share/fonts</dir>
<dir prefix="xdg">fonts</dir>
<!-- the following element will be removed in the future -->
<dir>~/.fonts</dir>