In the previous fifteen chapters of the book, the principles of rock mechanics and rheology have been outlined. They provide for a good basis for applications in structural geology and geotechnical engineering. General applications are therefore the start of this chapter. An important and moreover very interesting part of this chapter is the third paragraph, in which several noteworthy misconceptions and errors, persistently recurring in the geological literature are summarized. Limitations of the modern state-of-the-art rock mechanics and important topics requiring further research conclude this book and with that this chapter.