<s>
Barker	B-Application
's	I-Application
notation	I-Application
refers	O
to	O
the	O
ERD	B-Architecture
notation	O
developed	O
by	O
Richard	O
Barker	O
,	O
Ian	O
Palmer	O
,	O
Harry	O
Ellis	O
et	O
al	O
.	O
</s>
<s>
The	O
notation	O
was	O
adopted	O
by	O
Barker	O
when	O
he	O
joined	O
Oracle	B-Application
and	O
is	O
effectively	O
defined	O
in	O
his	O
book	O
Entity	B-Architecture
Relationship	I-Architecture
Modelling	I-Architecture
as	O
part	O
of	O
the	O
CASE	O
Method	O
series	O
of	O
books	O
.	O
</s>
<s>
This	O
notation	O
was	O
and	O
still	O
is	O
used	O
by	O
the	O
Oracle	B-Application
CASE	O
modelling	O
tools	O
.	O
</s>
<s>
It	O
is	O
a	O
variation	O
of	O
the	O
"	O
crows	O
foot	O
"	O
style	O
of	O
data	B-Application
modelling	I-Application
that	O
was	O
favoured	O
by	O
many	O
over	O
the	O
original	O
Chen	O
style	O
of	O
ERD	B-Architecture
modelling	O
because	O
of	O
its	O
readability	O
and	O
efficient	O
use	O
of	O
drawing	O
space	O
.	O
</s>
