I'm a hobbyist and as such I have an assorted collection of transistors. Most of them, if not all, have a cabalistic string after their names. Case in point is the 2N2222, which displays a "A331" right below its name. Other transistors may have different strings, but most of them show something.
I wonder what those strings mean. Google provided me a few scattered links about this subject, but none was satisfying.
On a separate issue, I find it a bit frustrating that I cannot identify a transistor's maker. There is obviously scarce room on a BJT transistor to print the maker's name, but that would help when one downloads a specific transistor's datasheet from that famous and quite useful AllDataSheet site. Instead of "A331" (or in addition to it thereof) they might have some identification string. Most transistors are made in China today, but they may differ slightly when it comes to their characteristics.
Thanks for any enlightenment on this topic.