Define and Use Custom Objects for PDF Metadata Signature
Metadata signature is a convenient way to sign documents using metadata properties. In GroupDocs.Signature for .NET 18.9, we introduced the feature of signing the PDF documents using various metadata properties including:
Author CreateDate MetadataDate CreatorTool ModifyDate Producer Entry Keywords Title Subject Description Creator You can set all or some of the above-mentioned properties while signing the documents. Since these are the built-in properties, you can only add/update their value.