This package is designed for typesetting the programmable elements in digital hardware, i.e. registers. Such registers typically have many fields and can be quite wide; they are thus a challenge to typeset in a consistent manner. Register is similar in some aspects to the bytefield package. Anyone doing hardware documentation using LaTeX should examine both packages. Register requires a fairly recent version of the float package. An example Perl module and a Perl script are provided to translate the register specifications into programmable data structures.