Returns or sets the parameter's marked state as a Boolean value. The 'marked state' is
true if the parameter is marked and false otherwise.
Marking parameters is a way of selecting which parameters you want
to use for a specific animation task. For example, you can mark
parameters so that only their animation is copied or removed, or
you mark the parameters you want to store in an action to be used
in the animation mixer. You can also mark parameters to be used
when scaling or offsetting an animation, or with linked parameters
or scripted operators.
Marking parameters is also one of the most common and useful tools
for setting keys. By marking only the parameters you need, you can
keep the animation information small.
The marking is set relative to the first group object (such as a
3DObject, Model or Group) in the parameter's path. If there is no
group object in the path then the markings are set relative to the
parameter's immediate parent.