You need to consult the datasheet. In the old days, a datasheet was bound into a printed book that was given to people who might use a manufacturers products in a new design. Now, through the magic of the internet, you can get almaost any datasheet you want by googling the part number. Most manufacturers post their datasheets in Adobe .pdf format so you can refine your search even further.
I have the datasheet but it doesn't seem to say which of the three pins is the base, emmittor and collector - it calls them something else. It calls the pins Tr or Th (or something like that i.e. not base, emmittor and collector!).
Don't know what you are looking at or where you got it from.
Here is the TIP31C and the BU406 from Fairchild. These two links were right at the top of the pile when I googled the part numbers. Why couldn't you do the same? I really don't understand.
:twisted: there many clown around i guess well no matter what you got looking at you if you think that is a device can can found out about it some of it. you need a VOM voltohmeter. for $5 on the resistance scale you can find out if that is an PNP,NPN diodes a transistor is 2 diodes anthow. but it could be FET and many other devices but an VOM will tell you more then some of these people can. take care
:twisted: there many clown around i guess well no matter what you got looking at you if you think that is a device can can found out about it some of it. you need a VOM voltohmeter. for $5 on the resistance scale you can find out if that is an PNP,NPN diodes a transistor is 2 diodes anthow. but it could be FET and many other devices but an VOM will tell you more then some of these people can. take care