Reasons for coordinate conditions in general relativity theory

Nonredefinition resulting from the basic grounds of the relativistic theory of tensor gravitational field, particularly, from general-covariant nature of its equations and manifesting by existence of Bianki identities is a peculiar feature of the equation system for Hilbert-Einstein gravitational field. Elimination of the nonredefinition of the gravitational field equations is exercised by derivation of four equations for a metrical tensor interpreted usually as conditions limiting the choice of the coordinate system and called the coordinate conditions