From the World Trade Organization:
After four years of negotiations and a year of work by WTO members on implementation measures and data collection, the WTO launched on Wednesday a new publicly available database on non-reciprocal preferential schemes.
The Transparency Mechanism for Preferential Trade Arrangements is a WTO agreement concluded in December 2010 which aims to increase members’ and the public’s understanding about the legal nature, history and background of each preferential trade arrangement (PTA), the range of products covered and the types of preferential treatment offered.
[The] database contains information on the preferential trade arrangements (PTAs) that are being implemented by WTO Members…PTAs are understood to mean non-reciprocal preferential schemes. They are distinct from regional trade agreements (RTAs), which are covered by the Transparency Mechanism for RTAs.