Rule 1: the Paper, which is made from diploma. In the manufacture of the applied diploma of special stamp paper, which is expensive to manufacture, and therefore to counterfeit it is rather difficult. So the first thing is to test the material paper. It should be quite hard, but pleasant to the touch, and have a peculiar specific odor chemical treatment of cellulose. The smell can not have plain paper in A4, and the touch different from the stamp of the sample.
Rule 2: No typos. Indeed, the grammatical errors in the text of the diploma and the error in the name of the specified person speak volumes.
Rule 3: you should Always contact the school which issued the diploma. Any of the educational institutions keeps strict accounting issued diplomas about education. In their registry must contain the number of the issued diploma, the full name of defending the diploma, evaluation of protection and date security. If, when you call to Secretariat of the institution, information was received that in the walls of the institution a certificate with these details never defended the diploma is a fiction.