No, we call jam jam. Jelly is made purely of the juice of a fruit or berry, thickened with pectin and with added sugar. If you use the whole fruit smooshed up but with chunks we call it preserves. We also call marmalade marmalade. It’s made primarily of the skin of citrus fruit, but you probably know that
The android build system used that limitation of Windows to prevent android from being built on Windows. They purposely had directories with the same name but different capitalization.