Portable Document Format (PDF) is a file format created by Adobe Systems for document exchange. PDF is used for representing two-dimensional documents in a manner independent of the application software, hardware, and operating system. Each PDF file encapsulates a complete description of a fixed-layout 2D document that includes the text, fonts, images, and 2D vector graphics which compose the documents.
The best way to view PDF files is locally using a reader. Several free readers for every system are available at pdfreaders.org.
This work is in the public domain in the U.S. because it is an edict of a government, local or foreign. See § 313.6(C)(2) of the Compendium of U.S. Copyright Office Practices, 3rd ed. 2014 (Compendium (Third)). Such documents include "legislative enactments, judicial decisions, administrative rulings, public ordinances, or similar types of official legal materials."
These do not include works first published by the United Nations or any of its specialized agencies, or by the Organization of American States. See Compendium (Third) § 313.6(C)(2) and 17 U.S.C. § 104(b)(5).
A non-American governmental edict may still be copyrighted outside the U.S. Similarly, the above U.S. Copyright Office Practice does not prevent U.S. states or localities from holding copyright abroad, depending on foreign copyright laws and regulations.