<dt><span>$conf['batch_download_max_elements']</span></dt>
<dd>Maximum value of the <b>Maximum number of photos per download set</b> slider.<br>
<i>Default is <span>1000</span>.</i></dd>

<dt><span>$conf['batch_download_max_size']</span></dt>
<dd>Maximum value of the <b>Maximum size of each archive</b> slider.<br>
<i>Default is <span>500</span>.</i></dd>

<dt><span>$conf['batch_download_additional_ext']</span></dt>
<dd>Array containing downloadable file extensions (case sensitive).<br>
<i>Default is <span>$conf['picture_ext']</span>.</i></dd>

<dt><span>$conf['batch_download_file_pattern']</span></dt>
<dd>Pattern for filenames in the archive.<br>
Available fields are <span>%id%, %filename%, %author%, %dimensions%, %name%, %expiry_date%</span>.<br>
Available functions are <span>$escape(xxx), $upper(xxx), $lower(xxx), $strpad(xxx, z, c)</span>.<br>
<i>Default value is <span>%id%_%filename%_%dimensions%</span>.</i><br>
<i>Example: <span>$strpad(%id%,4,0)_$escape(%filename%)_$lower(%author%)_%dimensions%</span>.</i></dd>

<dt><span>$conf['batch_download_use_representative_for_ext']</span></dt>
<dd>For a non image file, like a TIFF or a PDF, and for a multiple size (anything but the original) will the user download the original anyway or the according size of the preview (representative picture). The webmaster can configure Piwigo to decide for each file type.<br>
<i>Default is <span>array('tif', 'TIF', 'tiff', 'TIFF')</span></i><br>
<i>Example: <span>array('pdf', 'PDF', 'tif', 'TIF')</span></i></dd>

<dt><span>$conf['batch_download_guest_allowed']</span></dt>
<dd>Allow guest, ie not logged in visitors, to batch download files.<br>
<i>Default is <span>false</span>.</i></dd>

<dt><span>$conf['batch_download_configure_request_permission']</span></dt>
<dd>Before downloading users must request permission<br>
<i>Default is <span>false</span>.</i></dd>