(Optional; PDF 1.1) An action to be performed when the annotation is activated. Note: This entry is not permitted in link annotations if a Dest entry is present. Also note that the A entry in movie annotations has a different meaning.

(Optional; PDF 1.2) An appearance dictionary specifying how the annotation is presented visually on the page. Individual annotation handlers may ignore this entry and provide their own appearances.

(Required if the appearance dictionary AP contains one or more subdictionaries; PDF 1.2) The annotation’s appearance state, which selects the applicable appearance stream from an appearance subdictionary.

(Optional) An array specifying the characteristics of the annotation’s border. The border is specified as a rounded rectangle. In PDF 1.0, the array consists of three numbers defining the horizontal corner radius, vertical corner radius, and border width, all in default user space units. If the corner radii are 0, the border has square (not rounded) corners; if the border width is 0, no border is drawn. In PDF 1.1, the array may have a fourth element, an optional dash array defining a pattern of dashes and gaps to be used in drawing the border. The dash array is specified in the same format as in the line dash pattern parameter of the graphics state. For example, a Border value of [0 0 1 [3 2]] specifies a border 1 unit wide, with square corners, drawn with 3-unit dashes alternating with 2-unit gaps. Note that no dash phase is specified; the phase is assumed to be 0. Note: In PDF 1.2 or later, this entry may be ignored in favor of the BS entry.

(Optional; PDF 1.2) A border style dictionary specifying the characteristics of the annotation’s border.

(Optional; PDF 1.1) An array of three numbers in the range 0.0 to 1.0, representing the components of a color in the DeviceRGB color space. This color is used for the following purposes: • The background of the annotation’s icon when closed • The title bar of the annotation’s pop-up window • The border of a link annotation

(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.

(Optional) Text to be displayed for the annotation or, if this type of annotation does not display text, an alternate description of the annotation’s contents in human-readable form. In either case, this text is useful when extracting the document’s contents in support of accessibility to users with disabilities or for other purposes.

(Optional; PDF 1.1) A set of flags specifying various characteristics of the annotation. Default value: 0.

(Optional; PDF 1.1) The date and time when the annotation was most recently modified. The preferred format is a date string, but viewer applications should be prepared to accept and display a string in any format.

(Optional; PDF 1.4) The annotation name, a text string uniquely identifying it among all the annotations on its page.

(Optional; PDF 1.5) An optional content group or optional content membership dictionary (see 8.11, “Optional Content”) specifying the optional content properties for the annotation. Before the annotation is drawn, its visibility shall be determined based on this entry as well as the annotation flags specified in the F entry (see 12.5.3, “Annotation Flags”). If it is determined to be invisible, the annotation shall be skipped, as if it were not in the document.

(Optional except as noted below; PDF 1.3; not used in FDF files) An indirect reference to the page object with which this annotation is associated. This entry shall be present in screen annotations associated with rendition actions (PDF 1.5; see 12.5.6.18, “Screen Annotations” and 12.6.4.13, “Rendition Actions”)

(Optional; PDF 1.3) An indirect reference to a pop-up annotation for entering or editing the text associated with this annotation.

(Required) The annotation rectangle, defining the location of the annotation on the page in default user space units.

(Required if the annotation is a structural content item; PDF 1.3) The integer key of the annotation’s entry in the structural parent tree.

(Optional; PDF 1.5) Text representing a short description of the subject being addressed by the annotation.

(Required) The type of annotation that this dictionary describes.

(Optional; PDF 1.1) The text label to be displayed in the title bar of the annotation’s pop-up window when open and active. By convention, this entry identifies the user who added the annotation.

(Optional) The type of PDF object that this dictionary describes; if present, must be Annot for an annotation dictionary.