source: vendor/3.6.0/docs-xml/smbdotconf/printing/defaultdevmode.xml

<samba:parameter name="default devmode"
                 context="S"
                                 type="boolean"
                 print="1"
                 xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
<description>
    <para>This parameter is only applicable to <smbconfoption name="printable"/> services.
    When smbd is serving Printer Drivers to Windows NT/2k/XP clients, each printer on the Samba
    server has a Device Mode which defines things such as paper size and
    orientation and duplex settings.  The device mode can only correctly be
    generated by the printer driver itself (which can only be executed on a
    Win32 platform).  Because smbd is unable to execute the driver code
    to generate the device mode, the default behavior is to set this field
    to NULL.
    </para>

    <para>Most problems with serving printer drivers to Windows NT/2k/XP clients
    can be traced to a problem with the generated device mode.  Certain drivers
    will do things such as crashing the client's Explorer.exe with a NULL devmode.
    However, other printer drivers can cause the client's spooler service
    (spoolsv.exe) to die if the devmode was not created by the driver itself
    (i.e. smbd generates a default devmode).
    </para>

    <para>This parameter should be used with care and tested with the printer
    driver in question.  It is better to leave the device mode to NULL
    and let the Windows client set the correct values.  Because drivers do not
    do this all the time, setting <command moreinfo="none">default devmode = yes</command>
    will instruct smbd to generate a default one.
    </para>

    <para>For more information on Windows NT/2k printing and Device Modes,
    see the <ulink url="http://msdn.microsoft.com/">MSDN documentation</ulink>.
</para>
</description>

<value type="default">yes</value>
</samba:parameter>