Splicing systems are generative devices of formal languages, introduced by Head in 1987 to model biological phenomena on linear
and circular DNA molecules. In this paper we introduce a special class of finite circular splicing systems named marked systems. We prove that a marked system S generates a regular circular language if and only if S satisfies a special (decidable) property. As a consequence, we show that we can decide whether a regular circular language
is generated by a marked system and we characterize the structure of these regular circular languages.
Partially supported by MIUR Project “Automi e Linguaggi Formali: aspetti matematici e applicativi” (2005), by 60 % Project “Linguaggi formali e codici: problemi classici e modelli innovativi” (University of Salerno, 2005) and by 60 % Project “Linguaggi formali e codici a lunghezza variabile: proprietà strutturali e nuovi modelli di rappresentazione” (University of Salerno, 2006).