"Portable Document Format (PDF) is a file format for representing documents in a manner independent of the application software, hardware, and operating system used to create them and of the output device on which they are to be displayed or printed. A PDF document consists of a collection of objects that together describe the appearance of one or more pages, possibly accompanied by additional interactive elements and higher-level application data. A PDF file contains the objects making up a PDF document along with associated structural information, all represented as a single self-contained sequence of bytes. In order to optimize PDFs for minimum file size while still maintaining accessibility and search engine visibility, we can use compression techniques, for example, compression algorithms to reduce file size such as LZW, JPEG, JBIG2, Flate Decode, RunLength, JPEG2000, and CCITT, and reduce the complexity of the document that ultimately determines how large the resulting PDF file will be."
Yes they can show in the results..but you will have to them the same way you do any other page..use good keywords and optimization.