Principles

Interface Segregation Principle (ISP)

Many client specific interfaces are better than one general purpose interface.

Liskov Substitution Principle (LSP)

Functions that use references to base class must be able to use objects of derived classes without knowing it.

Open Close Principle (OCP)

A software entity (classes, modules, functions) should be open for extensions, but should be closed for modifications.

Single Responsibility Principle (SRP)

Ther should never be more then one reason for a class to change.