Section 1138, existing within the Galactic Republic Charter during the Cold War, was a specific clause. This clause mandated just and equitable treatment of prisoners of war by those who had captured them. When the Barsen'thor took Imperial Doctor Jurnak as a prisoner on Hoth, he invoked Section 1138, asking for an escort.
Within Star Wars media, Section 1138 is just one of the many references to George Lucas' initial feature film, THX 1138.