PDF Creator uses not only standard types like double, int, and so on, but also defines some custom types.

Standard and custom data types used in IPDFDocument4:

	AllowedChanges	These types are used to specify the changes allowed in a document.
	AllowedCopyLevel	These types are used to specify copy operations allowed in the document.
	AllowedPrintQuality	This type specifies the document's print quality.
	AnnotationBorderStyle	This type specifies the border style of an annotation.
	AnnotationType	This type specifies the kind of annotation (or control) to use.
	BlendMode	This type specifies available blend modes.
	BuiltInFont	This type specifies the 14 built-in fonts.
	ColorSpaceType	In a PDF file colors of graphic objects can be described in a device-independent way.
	CompressionType	This type allows enabling or disabling compression in a PDF document.
	DuplexType
	EmbedStyle	This type specifies how all fonts are to be stored in the PDF document.
	EncodingFormat	This type specifies the encoding format for the sample data used for sound annotations.
	EncryptionLevel	This type specifies the PDF document encryption level.
	FileAttachmentAnnotationIcon	This type specifies the icon used for file attachment annotations.
	FontCharset	This type specifies the character set for the font.
	FontStyle	This type specifies font styles.
	HRESULT	This type specifies the return value of COM functions and methods.
	ImageTransformation	This type specifies ways to transform an image.
	LayoutType	This type specifies the page layout to be used when the document is opened.
	LineCapStyle	This type specifies the shape to be used at the ends of open sub-paths (and dashes, if any) when they are stroked.
	LineJoinStyle	This type specifies the shape to be used at the corners of paths that are stroked.
	ModeType	This type specifies how to display the document in the viewer.
	PaperFormat	This type specifies page size as one of several predefined values (ISO paper sizes).
	PaperOrientation	This type specifies the orientation of the PDF document page.
	ParagraphAlign	This type specifies paragraph horizontal text alignment.
	PatternTilingType	This type specifies how patterns are tiled.
	RotateAngle	This type specifies the angle a page may be rotated clockwise.
	SoundAnnotationIcon	This type specifies the icon used for sound annotations.
	SubmitMethod	This type specifies the way a PDF form's field names and values are submitted.
	TextAlign	This type specifies horizontal text alignment.
	TextAnnotationIcon	This type specifies the icon used for text annotations.
	TextDirection	This type specifies the direction for text on the PDF page.
	TextRenderingMode	This type specifies the text rendering mode, which determines whether showing text causes glyph outlines to be stroked, filled, used as a clipping boundary, or some combination of the three.
	VerticalAlign	This type specifies vertical text alignment.
	ZoomName	This type specifies the PDF document page zoom level.