In copyright law, the P Line is specific to musical works (the P stands for “phonogram”) and is represented by ℗. The purpose of this symbol is to indicate that legal rights are held for a sound recording and to identify the owner of those rights. You may have seen this printed on an LP sleeve or CD booklet accompanied by the year that the work was first released and the name of the owner of the sound recording. For digital music the P Line is included within the metadata associated with an audio file.

The © symbol, or C Line, is used in relation to the underlying musical composition and lyrics and also to indicate copyright in a range of creative works other than sound recordings. In the context of music it is used to denote rights protection for the cover art or written material included within an album, like liner notes. Because the P Line and C Line refer to different rights you will always see them written separately, even when the owner of the rights is the same.