A data clip is a portion of a data stream.
In 2370, Elim Garak was able to retrieve files on Cardassian orphans of war and download them into a data clip. (DS9: "Cardassians") Later that year, Kellerun and T'Lani authorities provided a data clip to Starfleet of the security log of the laboratory where Miles O'Brien and Julian Bashir were thought to have been killed. (DS9: "Armageddon Game").