More examples for frequently required switches:
For "export_select=papers" the following parameters are often required:
form_export_papers_options[]=authors_extended                        // Add extra columns for authors
form_export_papers_options[]=authors_extended_firstname        // Output the authors in the format "first name last name"
form_export_papers_options[]=authors_extended_capitals                // Output the authors' surnames in CAPITALS
form_export_papers_options[]=authors_extended_presenters      // Add an * (asterisk) after each presenting author.
form_export_papers_options[]=authors_extended_columns                // List name, organization and e-mail in separate columns.
form_export_papers_options[]=abstracts                                // Include abstracts of submissions.
form_export_papers_options[]=reviews                                // Include review details.
form_export_papers_options[]=session                                // Include session information
form_export_papers_options[]=downloads                                // Include information about uploaded files.
form_export_papers_options[]=submitter                                // Include details about submitting person, like address and participant status.
form_track=-                        // Filter by Track/Strand
form_status=p                        // Export only submissions that will be presented.
form_include_deleted=0        // Do not export withdrawn submissions
form_export_format=xml      // Export in XML format OR use
form_export_format=xml_short // Export with XML format and leave out empty XML elements (with no data). This makes the export shorter.
form_export_header=default          // required
cmd_create_export=true          // required
For export_select=sessions the following parameters are advisable:
form_export_sessions_options[]=all
form_include_deleted=0
form_export_format=xml_short
form_export_header=default          // required
cmd_create_export=true          // required
Hints: 
- "
form_userID" can be used as additional filter for export_select=persons, papers, participants, attendees and event_participants
- The request string has to be "URL encoded", i.e., the brackets [] have to be written as %5B%5D
- Example request string (one line, of course the nonce and the passhash have to be replaced):   
https://www.conftool.pro/demo/pro/rest.php?nonce=1464279840616&passhash=abcdefgd737c49dbda6671f3d951ccaef3254e37&page=adminExport&export_select=papers&form_export_papers_options%5B%5D=abstracts&form_export_papers_options%5B%5D=session&form_export_papers_options%5B%5D=downloads&form_status=p&form_include_deleted=0&form_export_format=xml_short&form_export_header=default&cmd_create_export=true