SMC DIodes, perhaps unsurprisingly, offers a wide array of useful diodes for your discrete rectifier needs. Among them are their DSS series products, which we occasionally get marking questions about. The products’ datasheet seems to indicate a marking code of D12U, and further does not seem to call out other product sizes at all. What gives?
In this case, the answer is simple - the datasheet is for the whole product range, not a single product, with DSS12U simply being the first number in the series numerically and thus used as the example. Note that the marking information on Page 3 states “D12U = Marking Code”, and that the attributes table on Page 1 has a row called “Code”.
This piece of the datasheet gives the proper marking information and part number for each product in the series.