Multiple realities
(covers information from several alternate timelines)
CSS was an identifying prefix used before the names of space-faring ships of the Confederation of Earth.
An example of one such starship was the CSS World Razer. (PIC: "Penance")
The prefix was previously used on Earth during the 19th century to indicate ships that were operated by the Confederate States of America. An example of one such ship was the CSS Virginia. (TOS: "The Cage")