What is T-0 plank?

[Totte_S]

Checked some prices and selection on Beijer's website. What on earth is T-0?
Is it some sort of classification? I've never heard of it, is it something new?
C / K classification is used, but T?

 

[styrman1]

T-0 corresponds to what was called K12 and later T12.
T-0 is not stamped but there should be a certificate indicating that the timber meets that strength class.