Why does the Wiki not take Capital letter linking?

Like Hat vs hat

Do I have to code it as something else?

If you're talking about the recent posts not showing up for Hat, then it's a bug. http://trac.donmai.us/ticket/518

Okay.

There's a similar problem with the tag list, if you search for something capitalized it returns no results, these two issues are probably connected.

It seems the issue with Recent Posts not showing up with capital letters in wiki links has reappeared.

http://trac.donmai.us/ticket/1079

This also happens when someone uses a space rather than an underscore to link within the wiki itself.