Couplings covered by this standard are designed to accommodate parallel (or lateral) offset, angular misalignment, and axial displacement of the shafts without imposing unacceptable mechanical loading on the coupled machines.It is applicable to gear, metallic flexible element, quill-shaft and torsionally resilient type couplings. Torsional damping and resilient type couplings are detailed in Annex B, gear-type couplings are detailed in Annex C, and quill-shaft type couplings are detailed in Annex D.