The theme of this book is high-accuracy FD methods. Only for pseudospectral methods (Chapter 2) was the accuracy increased to its infinite order limit. Some compromises between order of accuracy and other features (such as handling of boundaries, numerical stability, etc.) are usually needed. This appendix focuses on cases where high orders of accuracy are readily achievable, but some of these orders can favorably be exchanged for the introduction of free parameters which then can be utilized for alternative purposes. Examples include increasing the wave number range for an FD scheme, enhanced Gregory quadrature, and accelerating ODE solvers for wave equations when using multicore processors.