Tires: Date of production code...which decade?

[beepbeep]

Hi!

There is a DOT-code on every tire explaining among other things which week and year tires have been produced.

But it's only one number for a year of production. So WXY234 means week nr. 23 year 1994 OR year 1984 ... how can i check in which year tires have been produced?

There is small arrow on the (right?) side of DOT-markings for tires made in 90's ... what does small line on each side of DOT-code means?

Thanx!

[beepbeep]

Nevermind ... i found it...small triangle = 90's ... everything else = too old.