The context associated with this instance includes the actual stream that represents the XObject Form and the initial conditions of the graphics state. The latter consists of the transformation matrix, initial color values, and so forth. It is possible to have two Forms that refer to the same XObject Form. The forms will exist at different places on the same page, depending on the transformation matrix. They may also have different colors or line stroking parameters. In the case of a transparency group, the opacity is specified in the gstate.

Within a Form, each element has its own gstate (or is a container, place, or group object). These gstates are independent of the parent Form gstate. Form elements may have their own opacity.

Content may be obtained from a Form to edit the form's display list.

Reference

ImGearPDEForm Members
ImageGear.Formats.PDF Namespace