<s>
Windows-1258	O
is	O
a	O
code	O
page	O
used	O
in	O
Microsoft	B-Application
Windows	I-Application
to	O
represent	O
Vietnamese	O
texts	O
.	O
</s>
<s>
Rather	O
,	O
it	O
is	O
very	O
similar	O
to	O
Windows-1252	O
,	O
with	O
the	O
differences	O
being	O
that	O
s-caron	O
and	O
z-caron	O
(	O
which	O
were	O
added	O
to	O
Windows-1252	O
later	O
)	O
are	O
missing	O
,	O
five	O
of	O
the	O
letters	O
with	O
diacritics	O
have	O
been	O
replaced	O
by	O
combining	O
diacritics	O
for	O
Vietnamese	O
tone	O
marks	O
,	O
one	O
has	O
been	O
replaced	O
with	O
the	O
đông	O
sign	O
,	O
and	O
eight	O
others	O
(	O
four	O
per	O
case	O
)	O
have	O
been	O
changed	O
to	O
four	O
otherwise-unsupported	O
Vietnamese	O
letters	O
.	O
</s>
<s>
Windows-1258	O
may	O
not	O
always	O
round-trip	B-Application
Unicode	O
encoded	O
Vietnamese	O
due	O
to	O
changes	O
caused	O
by	O
Unicode	O
normalization	O
.	O
</s>
<s>
IBM	O
's	O
code	B-General_Concept
page	I-General_Concept
1129	I-General_Concept
(	O
CCSID	O
1129	O
and	O
euro	O
sign	O
extended	O
CCSID	O
1163	O
)	O
is	O
similar	O
to	O
code	O
page	O
1258	O
,	O
but	O
with	O
the	O
following	O
differences	O
:	O
</s>
