Thank you for you reply,
Can you please tell me which method shows the yellow color note icon and where does this note data gets saved and method that get invoked when i open the pdf and it shows me the yellow icon of note.
the yellow icon, is a sticky note annotation and it's showed when the pdf page is rendered (like ink, rect or oval annotations).
All the informations about annotations are stored inside the pdf file (there is not an external data storage).
If you are interested in default icons types, you can take a look at setIcon method of PDFAnnot class.