Service mark symbol. The service mark symbol (â ), the letters SM in superscript style) is a symbol used in the United States to provide notice that the preceding mark is a service mark.
Size matters: The micro and mini USB connectors are of similar width. But the micro connector is much thinner (smaller vertical dimension). Some product designs were not able to accommodate the height of the mini receptacle and the new thinner receptacle will encourage and allow thinner products.
As a result, many device manufacturers began the miniaturization of USB connectors with this Mini-b. This 5-pin Mini-b is the most popular style of Mini-b connector, and the only one recognized by the USB-IF. By default, a Mini-b cable is presumed to have 5 pins.