This wiki is case sensitive on file names, and it is a real pain working with images with .PNG and .png being different.
I would suggest that the image upload policy be amended to the following, and this is based on the most common usages I've come across so far, so would basically be bringing images inline with the majority.
File Names
- use lower case extensions. For example .png rather than .PNG
- if the image name is multiple words then separate them with spaces, do not run them together or use hyphens. For example Ice amulet.png rather than Iceamulet.png
Ideally it would be nice if all file names were be lower case too - but for most images this isn't the case, so I'm not recommending that. Aka Edge 03:52, March 21, 2010 (UTC)
Update The image upload page already runs a find-and-replace on spaces to underscores in the "Destination filename" input box. It would be trivial to lower case the suggested destination filename and then it wouldn't matter what the filename looks like on the user's machine. This would fix most images uploaded from now on, as most people probably don't change the default value. Aka Edge 06:07, March 21, 2010 (UTC)
Discussion
Comment - Due to some image editors can only have in .PNG format there is a harder time for those people. Twig Talk https://i.imgur.com/772kZGs.png 03:58, March 21, 2010 (UTC)
- Oh i forgot one thing per what I said im Opposing Twig Talk https://i.imgur.com/772kZGs.png 04:19, March 21, 2010 (UTC)
Comment - If people are still uploading SD and jpeg images everyday, what makes you think they will abide by these rules? --Nup(T) 07:48, March 21, 2010 (UTC)
Oppose- A lot of people may have old computers and old systems which mean that they may not be able to do this, also there may be 2 pictures of the same thing but in different contexts then how do you separate them? That's not my best explanation but I can't think over a better way at the moment. 
Sentra246
09:20, March 21, 2010 (UTC)
Oppose - When I save something as a PNG, it comes out as .PNG. I'm sure many many many people also have this, so why not make .PNG the standard? Because there's also a lot of people who can save things simply as .png. It wouldn't work. 
Oil4 Talk 09:35, March 21, 2010 (UTC)
Comment - It doesn't matter what the files are saved as on people's own machines. They can use whatever programs and file names they like. All they need to do is change the "Destination File Name" box when they select the image. Sure, I understand there are plenty of users who will ignore this, but it's just a suggestion to make things easier (not harder) when working with images. Sentra's point about using case to distinguish different pictures is exactly my point too - Amulet.png and Amulet.PNG and aMulEt.PnG should not all be different things, use better descriptions like "unstrung amulet.png" and then when someone goes to include it on their page they'll get the right one, first time.
If I run a regex like this on list of item names: "(^.+$)" --> [ [ File:$1.png|$1 ] ] it should produce correct images more often than it currently does, because there isn't any guidelines on this at all at the moment. Aka Edge 20:35, March 21, 2010 (UTC)
Question - Why would we require this convention? You mentioned that working with .png and .PNG is a pain, but can you offer more specific reasons? This potential change would affect a lot of images and require a lot of file moves (hence a lot of work for admins). What are the benefits? If it's just personal preference, I don't think that justifies the change, if there's more, please let us know. 
Tollerach hates SoF 
21:20, March 21, 2010 (UTC)