<s>
Part	O
of	O
the	O
troff	B-Language
suite	O
of	O
Unix	B-Application
document	O
layout	O
tools	O
,	O
tbl	B-Application
is	O
a	O
preprocessor	O
that	O
formats	O
tables	B-Application
in	O
preparation	O
for	O
processing	O
with	O
troff/nroff	O
.	O
</s>
<s>
Mike	O
Lesk	O
is	O
the	O
original	O
author	O
of	O
tbl	B-Application
.	O
</s>
<s>
Like	O
the	O
main	O
troff	B-Language
program	O
,	O
it	O
uses	O
command	B-Application
lines	O
interspersed	O
with	O
data	O
to	O
be	O
printed	O
.	O
</s>
<s>
Because	O
of	O
the	O
nature	O
of	O
tabular	O
data	O
having	O
rows	O
and	O
columns	O
,	O
tbl	B-Application
commands	O
also	O
intraline	O
delimiters	O
for	O
fields	O
and	O
to	O
indicate	O
where	O
to	O
draw	O
lines	O
.	O
</s>
<s>
First	O
a	O
line	O
starting	O
with	O
.TS	O
,	O
followed	O
by	O
full	O
table	O
options	O
such	O
as	O
center	O
to	O
center	O
the	O
table	O
on	O
a	O
line	O
or	O
box	O
to	O
draw	O
a	O
box	O
around	O
it	O
(	O
boxes	O
in	O
tbl	B-Application
are	O
drawn	O
with	O
overlapping	O
hyphens	O
and	O
underscores	O
;	O
there	O
were	O
no	O
line	O
drawing	O
commands	O
at	O
the	O
time	O
of	O
creation	O
.	O
</s>
<s>
This	O
is	O
just	O
a	O
summary	O
of	O
tbl	B-Application
syntax	O
,	O
which	O
can	O
vary	O
in	O
small	O
details	O
from	O
implementation	O
to	O
implementation	O
.	O
</s>
<s>
GNU	O
troff	B-Language
(	O
groff	B-Application
)	O
,	O
Heirloom	O
troff	B-Language
,	O
and	O
mandoc	B-Application
contain	O
tbl	B-Application
implementations	O
.	O
</s>
