Media types - oldest =?

[jago25_98]

I would like to use a DVD burner to make backups for people.

But how can I be sure they will be able to read the DVD in thier player?

Which DVD media type is the oldest and thus will work in all players?

[DABhand]

Errrr these forums only give support for people wanting make backups for themselves. Not for giving away or selling or whatever your gonna do.

[jago25_98]

I'm backing up thier own hard drives.