Appending a text the Keyword property with existing text adds the double-quotation marks.

Hi,

When I add a text (keyword) in the Keyword property of the PDF that already has an existing keyword(s) it will automatically displays the double-quotation marks (").

However, using the same program statements above to add the text but in a PDF that does NOT have any text in the Keywords property yet, there are no double-quotes.

As an example, here are the lines to insert the text:

var pdfDocument = new Document(filename);

//specify document information

var docInfo = new DocumentInfo(pdfDocument);

var sbUpdatedKeywords = docInfo.Keywords;

sbUpdatedKeywords += !string.IsNullOrEmpty(sbUpdatedKeywords) ? cKeywordsConcat + keywords : keywords;  

docInfo.Keywords = sbUpdatedKeywords;  

//save output document

pdfDocument.Save(filename);

Also, when I view the raw PDF content using a hex or text editor, the Keywords does NOT have quotation marks even if it displays otherwise.

So, what can I do to "specify" don't show the quotation marks in any way (if that is possible)?