The catalogs of the Varios Especiales, items not included in the National Library's General Catalog, make available categories of printed material, such as brochures, pamphlets and tracts, which are of increasing importance to modern researchers. Once neglected because of their poor presentation and vast numbers, they are now valued as a rich resource for historical and cultural studies.

This wide-ranging collection of Varios Especiales has been divided into two periods and includes 16,000 records for the sixteenth and seventeenth centuries and 40,000 for the eighteenth and nineteenth.