The share of revenues granted to the music publisher via a publishing contract - depending on the type of publishing agreement (i.e. songwriter, co-publishing, sub-publishing, administration). Normally, the publisher's share can never exceed 50%. Depending on the type of publishing agreement, a publisher may acquire an "ownership share" in the copyrights for a period of time, including in perpetuity - this being the traditional and most common basis of an agreement. However, the ownership share and the collection share may differ, as in a typical co-publishing agreement.