Adding a custom mouse cursor
So you wanna add a custom mouse cursor to your mod? Well this is the page for you! (This tutorial will assume that you are using a ZIP-based format like PK3)
So the first thing you wanna go ahead and do is make sure that you have a folder called "graphics" in your PK3, if you don't, create it. Inside of the "graphics" folder, you wanna add in your custom mouse cursor graphic, I'd recommend the file name "cursor" (followed by the file extension).
One thing to note is that cursor graphics must be no larger than 32x32 pixels, otherwise they simply won't display and you will be left with the 'default' cursor. You can override this by assigning a HIRES graphic to the same name.
Now at the top-level of your PK3, add a MAPINFO, you won't need to create it if you already have one. Inside your MAPINFO.txt, write the following in your GameInfo section:
MAPINFO.txt (Inside of the GameInfo section)
CursorPic = "cursor"
Now when you bootup your mod, you should see a custom cursor.