What is 0h2 mean in guitar tab?

Question

INTRO:

e|------------------------------------...

B|------3---------3------------3------...

G|--------0---------0------------0----...

D|----0-------0h2----------0----------...

A|--2-------3-------------------------...

E|--------------------3-------------3-...

I am trying to learn Qing Tian - Jay Chou but im not sure what "0h2" means. Help is appreciated! Thanks!

Answer 1

It means that you hammer onto it on the second fret.  You play the unfretted and then quickly hammer your finger onto the second fret of the D string.

Answer 2

Open string/hammer/second fret.

What that means is that you play the D string with no fingers on the frets, and while the note is still ringing quickly place your finger on the second fret of the D string.