DVDIdentifier speed quesiton... rates in parens?

Forgive me if this has been covered before, but I can’t find it listed in the help file or online.

What does it mean when DVDIdentifier states a time as:
Recording Speeds: [1x (2x)]

What’s the significance of the ()s? I have one disc that’s reporting this way. What does it mean?

it shows the maximum recoring speed your blank dvd can write at.

I don’t think that’s true, I have other media that reports back at:
[1x 2x 4x]
none of the numbers are in () if what you said was true I’d suspect that 4x should be (4x) which it’s not.

How about this… is there a FAQ for DVDIdentifier? I don’t want to email the author if I don’t have to.