About New mount and item_db type 11

[XenaNyx]

who know when ride new mount can't use item like Fly Wing , Butterfly Wing ?

i see in db if item_db set type 11 if ride a new mount can't use item

601,Wing_Of_Fly,Fly Wing,11,60,,50,,,,,0xFFFFFFFF,7,2,,,,,,{ itemskill "AL_TELEPORT",1; },{},{}