Sound recording copyright symbol - Wikipedia
https://en.wikipedia.org/wiki/Sound_recording_copyright_symbolThe sound recording copyright symbol or phonogram symbol, represented by the graphic symbol ℗, is the copyright symbol used to provide notice of copyright in a sound recording (phonogram) embodied in a phonorecord (LPs, audiotapes, cassette tapes, compact discs, etc.). It was first introduced in the Rome Convention for the Protection of Performers, Producers of Phonograms and Broadcasting Organisations. The United States added it to its copyright law as part of its adherenc…