<s>
In	O
a	O
technical	B-Application
drawing	I-Application
,	O
a	O
basic	B-Application
dimension	I-Application
is	O
a	O
theoretically	O
exact	O
dimension	O
,	O
given	O
from	O
a	O
datum	O
to	O
a	O
feature	O
of	O
interest	O
.	O
</s>
<s>
In	O
Geometric	B-Application
dimensioning	I-Application
and	I-Application
tolerancing	I-Application
,	O
basic	B-Application
dimensions	I-Application
are	O
defined	O
as	O
a	O
numerical	O
value	O
used	O
to	O
describe	O
the	O
theoretically	O
exact	O
size	O
,	O
profile	O
,	O
orientation	O
or	O
location	O
of	O
a	O
feature	O
or	O
datum	O
target	O
.	O
</s>
<s>
Basic	B-Application
dimensions	I-Application
are	O
currently	O
denoted	O
by	O
enclosing	O
the	O
number	O
of	O
the	O
dimension	O
in	O
a	O
rectangle	O
.	O
</s>
<s>
When	O
features	O
are	O
located	O
using	O
BASIC	B-Application
dimensions	I-Application
by	O
chain	O
dimensioning	O
,	O
there	O
is	O
no	O
accumulation	O
of	O
tolerance	O
between	O
features	O
,	O
because	O
the	O
dimensions	O
refer	O
to	O
the	O
theoretically	O
perfect	O
position	O
of	O
the	O
feature	O
,	O
not	O
the	O
actual	O
location	O
of	O
the	O
feature	O
within	O
the	O
range	O
permitted	O
by	O
tolerances	O
.	O
</s>
<s>
Basic	B-Application
dimensions	I-Application
,	O
identified	O
by	O
the	O
engineer	O
,	O
locate	O
Because	O
that	O
’s	O
true	O
,	O
basic	B-Application
dimensions	I-Application
identify	O
tolerance	O
information	O
located	O
in	O
feature	B-Application
control	I-Application
frames	I-Application
that	O
state	O
geometric	B-Application
tolerances	I-Application
.	O
</s>
<s>
When	O
an	O
engineer	O
makes	O
a	O
statement	O
of	O
tolerance	O
,	O
that	O
statement	O
is	O
made	O
in	O
the	O
form	O
of	O
a	O
feature	B-Application
control	I-Application
frame	I-Application
.	O
</s>
