Advertising of procurement opportunities and contract award results is a foundation stone of public procurement. Full and open advertising facilitates appropriate competition, develops markets and helps in the battle against corruption. SIGMA Brief 6 provides the reader with guidance on where and when notices for contracts subject to the European Union public procurement Directives must be advertised. It also provides information on other methods of keeping the market informed. It gives guidance on the correction of contract notices which contain incorrect information, on how to complete and dispatch contract notices electronically, and special rules for Utilities.