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.
TransFlash and microSD cards are functionally identical allowing either to operate in devices made for the other. I have no doubt you know more about this subject of micro sdhc/sdxc cards vs. micro sdhc/sdxc tf cards. HOWEVER- I have had some vexing experience that makes me suspect there IS some difference. I bought some nice micro sd to USB 2.0/3.0 adapters on eBay.