[FORMAT] what are the sections into a ps file ?

[yp56]

Hello,
I want to creaye a posctscript file. But what are needed sections ?

Here is my ps :

----------------------------
%!PS-Adobe-3.0
%%Pages: 2
%%EndComments
%%Creator: RiePS
%%CreationDate: 2007/05/09 10:43:02
%%EndComments
50 dict
begin
....
.....
%%Page : 1 2
....
....
%%EndPage
showpage
%%Page : 2 2
....
...
%%EndPage
showpage
end
%EOF

-----------------------
Where must I write %%BoudingBox 0 0 w h ? and setpagedevice ? Are there other sections to write ?

thanks