text: (E/ECA/TRADE/3) was revised to include additional data and case studies were carried out on domestic trade structures, mechanisms and distribution channels in Sierra Leone, Senegal and Mali. (b) Intra-African trade 63. Secretariat activities concentrated on assistance to subregional institutions such as the Preferential Trade Area for Eastern and Southern African States (PTA), the Economic Community of Central African States (ECCAS) and the Economic Community of West African States (ECOWAS). The ECA secretariat prepared, at the request of the PTA secretariat, a number of technical papers on the Common List of Products to be Traded in PTA, the Manual on Customs Co-operation within PTA and a technical study on product—by—product tariff negotiations and gradual removal of non-tariff barriers. - 25 - 64. In the Central African subregion, the secretariat continued to assist the newly established secretariat of the Economic Community of Central African States to implement the Treaty and its protocols. The main studies carried out by January 1985, with UNDP financial assistance, were aimed at proposing concrete measures for the reduction and/or elimination of tariff and non-tariff barriers for products to be traded within the Community. Assistance to the MULPOCs was accorded very high priority. (c) Trade information and trade promotion 65. The secretariat carried out its trade information, marketing research and trade promotion activities through the Africa Trade Centre in the International Trade and Finance Division and concentrated on three main areas: trade and finance information, trade promotion and advisory services and training. In addition to the publication of five issues of "Flash on Trade Opportunities" and three issues of the "African Trade Bulletin", the Centre prepared profiles of African countries for the African Trade Directory to be published in the last quarter of 1985. Preliminary work was also undertaken on the establishment of an African Trade Information 
analysis: The text primarily discusses the activities of the Economic Commission for Africa (ECA) in the fields of trade and economic development, with a focus on intra-African trade, trade information, and trade promotion. It also mentions assistance to regional institutions and the establishment of an African Trade Information System.