Hi, First of all thank you all for giving me suggestions & comments. I made changes to the previous patch and attached the new patch for getting/setting PDF ID. I attached the patch without having the API Documentation. I will do it as early as possible. I think I made indentation correctly this time. Mean while, send me suggestions/comments about this patch. If possible tell me how to add API documentation. @Carlos Garcia : I also thought that PDFDoc::SaveAS() will set the ID in the document. But that is not always. In PDFDoc::saveAs(GooString *filename,PDFWriteMode mode). We have to pass the mode as writeForceRewrite then only it generates the ID and set it. But I tried with some PDF files, It is setting the ID in the trailer dictionary, but it is loosing the data. I don't know why it is happening. If you want you can check I attached that PDF (bigtable-osdi06.pdf) file also. It has happened for all pdf files I have checked so far. Thanks -- A srinivas