rider / mount animation

[Mahdi]

Hi, I checked my rideable mounts resp. mount items (0x3ea2 etc.) and its animations. I am confused because horse which is ok in game (for example mount item 0x3ea2) has in tiledata animation ID-0x338. This ID is empty!!! In Bodyconv.def, Body.def or Anim1.def isnt ID used. So I change ID from 0x338 to 0xCC - where is animation of this horse. But this make more problems. The rider animation doesnt match to mount animations and rider is stucked in mount (rider is lower). I tried to change mobtype of animation 0xCC to fix animation match but it didnt work.

So my question:
Animation 0x338 is empty. Animation isnt used in body.def, bodyconv.def, Anim1.def - How can client display mounted horse?

Is really necessary to use animation ID from OSI tiledata?

How can I make new mount item if I want use other animation?

Thanks for help.