What are the required PDF specifications?

We advise the following PDF settings:

• Non-flattened Acrobat 5 (PDF 1.4) file
• First page (cover) should be included as single page, subsequent pages can be included as single pages or spreads
• Check for all pages if the TrimBox is set right
• Automatic maximum quality JPEG compression
• Don't convert text to outlines (embed fonts) as otherwise the text can not be indexed by search engines
• Preferably 300 dpi
• Maximum 100 MB
• Don't separate URLs and email addresses in your text by line breaks and add a blank space on each side of the URL/email address
• If you have added link frames in your PDF, make sure that these are smaller than the actual page

Click here for some screenshots showing how you can export a PDF from Adobe InDesign.