why does tag XResolution return a List?

[Robert Wassens]

After updating from 0.5.0 to 0.6.0 I got a pattern matching error. It appear the tag XResolution in the decoder gives a List, whil before it did not:

decoder.find_tag(Tag::XResolution)?
Returns in 0.6.0:
Some(List([Rational(250000000, 250000000)]))

In 0.5.0 it returns:
Some(Rational(250000000, 250000000))

Is this intentional?