The Federation Uniform Code of Justice was a system of laws for Federation citizens. In this system, a citizen was innocent until proven guilty, and, if innocent, would be set free. (TNG: "The Drumhead"; DS9: "The Maquis, Part II")
When being questioned by Admiral Norah Satie in 2367, Captain Jean-Luc Picard cited Chapter Four, Article Twelve of the Uniform Code of Justice, which granted him the right to make a statement before questioning began. (TNG: "The Drumhead")
In 2370, a group of Maquis prisoners were scheduled to be tried under the Federation Code of Justice. (DS9: "The Maquis, Part II")
Although referred to as the Federation Uniform Code of Justice in the script, the word "Federation" was dropped on screen in "The Drumhead" and the word "uniform" was dropped in "The Maquis".
The relationship between the Federation Uniform Code of Justice and the Federation Judicial Code
is unclear. The two may be synonymous.