An avatar’s prepare pose is its pose as used in prepare mode. The default pose is the bind pose: the pose which is bound to the avatar skeleton.
If an avatar - parametric or imported - has a skeleton and multiple poses, you can change the prepare pose.
For example, on entering prepare mode it may be that the avatar’s pose is not the best starting point to complete garment preparation. Therefore, changing the pose can help.
To change the prepare pose:
Load the avatar into the 3D window.
On the Main menu, click 3D Environment, Avatar, then Prepare Pose. The available poses are displayed.
Click the pose you want to use as the prepare pose.