Anthony Fredrickson was a Starfleet officer in the 24th century.
In 2372, he was listed as a member of the Science Ops team on the dedication plaque of the USS Defiant. (DS9: "The Die is Cast", dedication plaque)
The same year, he was also listed as a member of the Systems Management team on the dedication plaque of the USS Enterprise-E. (Star Trek: First Contact, dedication plaque)
Later yet that same year, he was listed as a Tactical Ops officer on the dedication plaque of the USS Valiant. (DS9: "Valiant", dedication plaque)
In 2375, he was listed as a Science Ops team member, once again, on the dedication plaque of the USS Sao Paulo. (DS9: "The Dogs of War", dedication plaque)
This character was only mentioned in writing.