Single-window system Single-window system The single-window system is a trade facilitation idea. As such, the implementation of a single window system enables international (cross-border) traders to submit regulatory documents at a single location and/or single entity. Such documents are typically customs declarations, applications for import/export permits, and other supporting documents such as certificates of origin and trading invoices. The main value proposition for having a single window for a country or economy is to increase the efficiency through time and cost savings for traders in their dealings with government authorities for obtaining the relevant clearance and permit(s) for moving cargoes across national
Single (music) released as a single may not appear on an album. As digital downloading and audio streaming have become more prevalent, it is often possible for every track on an album to also be available separately. Nevertheless, the concept of a single for an album has been retained as an identification of a more heavily promoted or more popular song (or group of songs) within an album collection. Despite being referred to as a single, singles can include up to as many as three tracks. The biggest digital music distributor, iTunes Store, accepts as many as three tracks less than ten