a) it is a photographic work and 50 years have passed since its creation;
b) it is a computer program, audio-visual work or sound recording and 50 years have passed since the date of its first publication;
c) it is a literary, musical or artistic work that was published before January 1st, 1954 and its author died before Jan 1st, 2004;
d) it is a Government work and 50 years have passed since its first publication;
e) it is another type of work and 50 years have passed since the author's death.
To the uploader: Please provide authorship and publication details.