May foodstuffs intended for particular nutritional uses contain also substances which are not listed in Annex 13 to Decree No 54/2004 Coll.?

Yes, but the assessment and authorisation of foodstuffs intended for particular nutritional uses is not within the powers of SÚKL and it is necessary to contact the Ministry of Health of the Czech Republic, department of Public Health Protection.  

The marketing of these foodstuffs is regulated by Act No 110/1997 Coll., as amended, and by Decree No 54/2004 Coll., as amended. The quoted legal regulations, furthermore, stipulate the obligations of the manufacturer or importer prior to the marketing of these foodstuffs.