This is more of a general Solidworks question.

As far as I can tell, these were saved in exactly the same manner.  I didn't change the case.  Something else changed it.

I have noticed this over the years and never really thought much of it.   Today, I ran into it and thought....let's ask.

Below is another example:

Here, in the BOM, when I RMB on the part, it shows up lower case:

In fact, for every part in the BOM the "Open.." spot on the RMB tree is all lower case.

But when I open that part, you can see that it is Upper case in the actual file name and the title at the top of the tree:

When I create a drawing of it, all upper case:

I find this odd, because in order to make it lower case, Solidworks programmers have you have to to specify it to be lower case because it was saved in uppercase.  It seems like this was done on purpose, but I don't understand it.

The only reason that I really bring this up is that at one point, we (​ and I) were having an issue with part templates in which, which seemed to stem from uppercase template extensions vs lowercase template extensions.  ​ resolved the issue, but I just wonder......

Why?

SW 2015 Sp5 / Windows 10 64bit.