What is the name of the primary symbol, which is now outlawed outside of the context of art or science, and was widely used even on the state flag?
Strafgesetzbuch section 86a The German "Strafgesetzbuch" (Criminal Code) in § 86a outlaws "use of symbols of unconstitutional organizations" outside of the contexts of "art or science, research or teaching". This concerns Nazi symbolism in particular and is part of the denazification efforts following the fall of the Third Reich.
Doug flag The Doug flag, also referred to as the Cascadian flag or the Cascadia Doug flag and nicknamed "Old Doug" or simply "the Doug", is one of the primary symbols and an unofficial flag of the Cascadia bioregion, which roughly encompasses the U.S. states of Oregon and Washington, the Canadian province of British Columbia, and other parts of North America's Pacific Northwest. It was designed by Portland, Oregon native Alexander Baretich in the academic year of 1994-1995.