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.
Two types of mini USB connectors were developed; namely, USB mini A and USB mini B. These connectors are 3 x 7 mm in size and are often used in mobile devices such as camcorders. There is an extra pin compared to the standard USB connector, know as ID pin, which was introduced for further development of the standard.