I had an old hard drive I wanted to use as a secure, cross platform file transfer device, so I thought of TrueCrypt and UDF. Unfortunately, TrueCrypt for MacOS only supports formatting drives as Mac OS Extended and TrueCrypt for Windows only supports NTFS and FAT32. I ended up using TrueCrypt for Mac OS and the Mac’s command line formatting utility.

1. Login as an Administrator
2. Connect the drive you want to protect with TrueCrypt
3. Open TrueCrypt and create a TrueCrypt Volume like normal, but select "None" when asked to select a filesystem
4. Wait for the encryption to complete
5. From TrueCrypt, click the "Select File…" or "Select Device…" to select your newly encrypted volume and click "Mount"
6. Enter the password and any other authentication credentials required for the Volume. Check "Do not mount" before clicking "OK"
7. Back in the main TrueCrypt window, select the Volume and click "Volume Properties…"
8. Record the Virtual Device value. In this case "/dev/disk3"
9. Open a Terminal window
10. Run sudo newfs_udf /dev/disk3 to format the TrueCrypt volume with the UDF filesystem
11. From now on, the UDF filesystem will automatically be mounted when mounting the TrueCrypt volume on Window or Mac OS