4.3BSD/usr/contrib/spms/doc/layer.tbl

.TS
center box;
c | c
n | a.
Layer	Components
=
1	Shared source code
	(header files)
_
2	Shared object code
	(program libraries)
_
3	Programs
_
4	Data files
_
5	Documentation
	T{
.na
(reference manual, user's guide, etc.)
.ad
T}
.TE