<s>
The	O
so-called	O
or	O
PI	O
(	O
English	O
:	O
Prussian	O
instructions	O
)	O
are	O
a	O
cataloging	B-Library
set	O
of	O
rules	O
for	O
libraries	O
which	O
was	O
used	O
in	O
scientific	O
libraries	O
in	O
German-speaking	O
countries	O
and	O
beyond	O
.	O
</s>
<s>
Already	O
in	O
1874	O
(	O
hectographed	O
edition	O
)	O
and	O
1886	O
(	O
printed	O
edition	O
)	O
,	O
Karl	O
Franz	O
Otto	O
Dziatzko	O
of	O
the	O
University	O
Library	O
at	O
Breslau	O
had	O
presented	O
a	O
set	O
of	O
cataloging	B-Library
rules	O
under	O
the	O
title	O
""	O
,	O
also	O
known	O
as	O
""	O
(	O
English	O
:	O
Wroclaw	O
instructions	O
)	O
.	O
</s>
<s>
Despite	O
their	O
role	O
model	O
,	O
it	O
was	O
often	O
not	O
possible	O
to	O
achieve	O
a	O
uniform	O
and	O
fully	O
consistent	O
application	O
of	O
the	O
guidelines	O
in	O
the	O
cataloging	B-Library
of	O
some	O
important	O
libraries	O
in	O
Bavaria	O
,	O
Hesse	O
,	O
Saxony	O
and	O
at	O
other	O
traditional	O
German	O
library	O
locations	O
before	O
the	O
introduction	O
of	O
digital	O
computers	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
library	B-Library
catalogs	I-Library
following	O
keywords	O
or	O
correspondingly	O
structured	O
directories	O
,	O
knowledge	O
of	O
these	O
rules	O
is	O
still	O
helpful	O
,	O
however	O
.	O
</s>
