troff/nroff quick reference.

formatting
- breaking and filling
- motion
- fonts
- hyphenation
- spaces
- traps

existentials
- command line options
- input, output, and abort

macros
- defining troff macros
- number registers and units
- string registers
- the ms macros, prologue

slow reference
- Kernighan/Ossanna CSTR #54 pdf
- Kernighan/Ossanna CSTR #54 ps.gz
- Basic formatting with troff/nroff.


(Thanks to Michael Bishop for pointers and the PDF conversion of Computing Science Technical Report #54.)