Will one data partition cover 3 OS's?

I've made some changes on my desktop and was wondering if one data partition will cover 3 Windows OS's, even if they're not the same OS.

My main install on the desktop in Win 7 Pro x64, but I've setup a tri-boot, the other OS's are XP Pro & XP Pro x64 (still trying to decide which I'll keep, 1 will go). Usually, when I make data partitions for an OS, they typically contain the same things, meaning that I have a lot of duplicate items (downloads, picture/video folders & VM's). Eliminating 2 partitions would not only save drive space, but backup space also.

Will all OS's have read/write access to a single data partition?

Cat

As long as it has a drive letter assigned to it from each os.