(Optional; PDF 1.4) The constant opacity value to be used in painting the annotation. This value applies to all visible elements of the annotation in its closed state (including its background and border) but not to the popup window that appears when the annotation is opened. The specified value is not used if the annotation has an appearance stream; in that case, the appearance stream must specify any transparency. (However, if the viewer regenerates the annotation’s appearance stream, it may incorporate the CA value into the stream’s content.) The implicit blend mode is Normal. Default value: 1.0.

public const string CA

Public Const CA As String

public:
literal String^ CA