Why use the "UDF 2.5" Imgburn option when making an ISO?

[john.blue]

So I have been digging around a little bit, but I cannot find the answer to a question that has been bugging me. In this guide:

http://forum.slysoft.com/showthread.php?t=15801

the direction is:

-In options, make SURE UDF 2.5 is selected. VERY IMPORTANT!

In my searching I have learned that Bluray's use UDF 2.5 and one needs to install additional drivers for Windows XP to read a Bluray disk. What I would like to know is what happens if an ISO is made and UDF 2.5 is not selected? And do I need to select the UDF 2.5 option *only* if I am ripping a Bluray disk? If so, what should the UDF option be set to for regular DVD's and HD-DVD's?

I ask about the regular DVD settings because I have an HDX 1000 media tank. So far I have ripped all of my kids DVD's to make ISO's out of without making any adjustments to the UDF setting in Imgburn and they play great on the media tank.

Thanks.

 

[mike_r]

If you don't select UDF2.5 and burn your ISO onto a disc, and insert this disk into a standalone player - then it will not work.

If you are ripping, then the UDF option doesn't play a role.

HD-DVDs are UDF2.6