Open from a removable medium

    This button allows you to open a document from a removable medium : cd rom, usb key etc...
    When you push this button, you are asked to give the path  of the medium e.g. /mnt/removable or
/Users/Volumes/usb_key depending on your medium and your O.S.. This path is kept so the next time it will not be necessary to type it again.