Prevent the opening of PDF-files in the browser
When you click on a link to a PDF-document in SharePoint, it can open either within the web browser or directly in Adobe Reader. Each browser has its own settings to control how PDFs open …
Configuring SharePoint to allow opening PDF files and other “non-trusted” file types from a browser
By default, SharePoint doesn’t consider file-types such as PDF documents to be save for opening from a browser. SharePoint adds an additional security header and the browser will force the user to save the files …