>it doesn't in spec, that's just the win32 API
NTFS filename length is limited to 255 Unicode chars.
You may be thinking of full path lengths of 32,767 Unicode chars but the filename component is still limited to 255.
If you look at the NTFS data structure "$FILE_NAME (0x30)" at byte offset 0x40: https://www.google.com/search?q=ntfs+%22%24FILE_NAME%22+byte
... there's only 1 byte used to describe the filename length. Hence max of 255 chars.
Wikipedia page about NTFS also mentions 255 max length for filename: https://en.wikipedia.org/wiki/NTFS
You're confusing the filename length limit with the limitation on the entire path length in the Windows API. NTFS allows paths to be up to 32k characters long, but each path component tops out at 255 characters.
it doesn't in spec, that's just the win32 API