| Class | Description |
| PdfAnnotation | Provides the base class that contains information about PDF annotation. |
| PdfAnnotationAdditionalActions | Stores additional-actions defining the annotation's behavior in response to various trigger events. |
| PdfAnnotationAppearanceCharacteristics | Stores appearance characteristics to be used in constructing a dynamic appearance stream specifying the annotation visual presentation on the page. |
| PdfAnnotationAppearanceGenerator | Represents a base class of appearance generators for PDF annotations. |
| PdfAnnotationAppearances | Represents the appearances, which are specifying how the annotation is presented visually on the page. |
| PdfAnnotationBorderEffect | Stores information about border effect of PDF annotation. |
| PdfAnnotationBorderStyle | Stores information about border style of PDF annotation. |
| PdfAnnotationCodec | Provides the base abstract codec that allows to export and import PDF annotations. |
| PdfAnnotationEventArgs | Provides data for PDF annotation events. |
| PdfAnnotationIconFit | Specifies how to display the widget annotation's icon within its annotation rectangle. |
| PdfAnnotationList | Represents a collection of PdfAnnotation objects. |
| PdfAnnotationsRelationsHelper | Contains methods to simplify work with annotations relations. |
| PdfAnnotationXfdfCodec | Exports PDF annotations to XFDF format and imports PDF annotations from XFDF format. |
| PdfCaretAnnotation | Represents a PDF annotation that displays a visual symbol that indicates the presence of text edits. |
| PdfCaretAnnotationAppearanceGenerator | An appearance generator for a PDF caret annotation. |
| PdfCircleAnnotation | Represents a PDF annotation that displays a circle. |
| PdfCircleAnnotationAppearanceGenerator | An appearance generator for a PDF circle (ellipse) annotation. |
| PdfFileAttachmentAnnotation | Represents a PDF annotation that stores a file attachment. |
| PdfFileAttachmentAnnotationAppearanceGenerator | An appearance generator for a PDF File Attachment annotation. |
| PdfFreeTextAnnotation | Represents a PDF annotation that displays an editable text area and a callout line used to point to the area of PDF page. |
| PdfFreeTextAnnotationAppearanceGenerator | An appearance generator for a PDF free text annotation. |
| PdfInkAnnotation | Represents a PDF annotation that displays a freehand lines composed of one or more disjoint paths. |
| PdfInkAnnotationAppearanceGenerator | An appearance generator for a PDF Ink annotation. |
| PdfLineAnnotation | Represents a PDF annotation that displays a line. |
| PdfLineAnnotationAppearanceGenerator | An appearance generator for a PDF line annotation. |
| PdfLinkAnnotation | Represents a PDF annotation that displays a link. |
| PdfLinkAnnotationAppearanceGenerator | An appearance generator for a PDF link annotation. |
| PdfMarkupAnnotation | Provides the base class that represents a PDF markup annotation. |
| PdfOfficeDocumentAnnotation | Represents a VintaSoft PDF annotation that stores a office document. |
| PdfPaperMetaDataGenerationParameters | Contains information about PaperMetaData generation parameters, which contains instructions to a barcode encoding module of a conforming reader on how to generate the barcode image. |
| PdfPolygonalAnnotation | Provides the base class that represents a PDF point-based (polyline, polygon) annotation. |
| PdfPolygonalAnnotationAppearanceGenerator | An appearance generator for a PDF polygonal (polygon, polyline) annotation. |
| PdfPolygonAnnotation | Represents a PDF annotation that displays a polygon. |
| PdfPolygonAnnotationAppearanceGenerator | An appearance generator for a PDF polygon annotation. |
| PdfPolylineAnnotation | Represents a PDF annotation that displays a polyline. |
| PdfPolylineAnnotationAppearanceGenerator | An appearance generator for a PDF polyline annotation. |
| PdfPopupAnnotation | Represents a PDF annotation that displays text in a pop-up window for entry and editing. |
| PdfProjectionAnnotation | Represents a projection annotation (PDF 2.0) that has much of the functionality of other markup annotations. |
| PdfRectangularAnnotation | Provides the base class that represents PDF rectangular (square, circle) annotation. |
| PdfRectangularAnnotationAppearanceGenerator | An appearance generator for a PDF rectangular (square, circle) annotation. |
| PdfRubberStampAnnotation | Represents a PDF annotation that displays a rubber stamp. |
| PdfSquareAnnotation | Represents a PDF annotation that displays a square. |
| PdfSquareAnnotationAppearanceGenerator | An appearance generator for a PDF square annotation. |
| PdfTextAnnotation | Represents a PDF annotation that displays a "sticky note" attached to a point in the PDF document. |
| PdfTextAnnotationAppearanceGenerator | An appearance generator for a PDF text (comment) annotation. |
| PdfTextMarkupAnnotation | Represents a PDF annotation that can appears as highlight, underline, strikeout, or jagged ("squiggly") underline in the text of document. |
| PdfTextMarkupAnnotationAppearanceGenerator | An appearance generator for a PDF text markup annotation (highlight, underline, strikeout, squiggly). |
| PdfWidgetAnnotation | Represents a PDF Widget annotation that displays interactive element. |