The main principle of business correspondence is to communicate clearly to the addressee. Another principle of business correspondence is to appropriately represent the organization and person sending the correspondence, that is, to make sure they are represented in a professional, businesslike manner.

The correspondence principle has applications to macroscopic events in the everyday macro-world. This principle is a general rule not only good for science but for all good theory - even in areas as far removed from science as government, religion, and ethics. If a new theory is valid, it must account for the verified results of the old theory.

in correspondence to or of

"Modern Physics" is a heading commonly used to introduce the studies of light and

Quantum Physics, the Correspondence Principle, the Uncertainly Principle, Waves

and Particles, Wave Mechanics and the Schrödinger Probability equation, nuclear

physics, and Relativity.

The differences in personal correspondence and business correspondence are tone and form. The form and tone of business correspondence is more professional.