The authors analyzed all conventions that exist and classified according to the following three signs (S1, S2, S3)::formula_12The third sign above is related to the choice of convention for the Ricci tensor::formula_13With these definitions Misner, Thorne, and Wheeler classify themselves as formula_14, whereas Weinberg (1972) is formula_15, Peebles (1980) and Efstathiou (1990) are formula_16 while Peacock (1994), Rindler (1977), Atwater (1974), Collins Martin & Squires (1989) are formula_17.