CSS-validator:questions

Dear Sir, Philippe,

How are you?

I tried to validate the following stylesheet, but keep on getting errors from the CSS-validator. After consulting http://www.w3.org/tr/rec/css2/page.html I still do not understand why those errors are given. I would like you to spend a short moment for this case. 

STYLESHEET:

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@media print, projection {
@page:left {margin-left:5%
 margin-right:10%;
 size:auto;
}
@page:right {margin-right:5%;
 margin-left:10%;
 size:auto;
}
@page:first {margin-top:10%
}
@page rotated {size: 29.7cm 21.0cm
}
tabel {page:rotated;
 page-break-before:right;
}
h1, h2, h3, h4, h5, h6    { page-break-after: avoid;
 page-break-inside: avoid;
}
pre {page-break-inside:avoid;
}
ul, ol, dl {page-break-before:avoid;
}
p {orphans:2;
 widows:2;
}
}

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ERRORS GIVEN:

Fouten :
  a.. 
    URI : http://www.xs4all.nl/~fini/css/print.css 
    Regel: 5 
    Parse Error - @page:left {margin-left:5% margin-right:10%; size:auto; } 
    Regel: 11 Ongeldig getal : margin-top 
    Parse Error - } 
    Regel: 13 Ongeldig getal : size 
    Parse Error - } 
    Regel: 27 
    Parse error - Unrecognized : } 
  b.. 

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It appears to me that bracket's should be closed (27). 
Margin given in % or cm should be allowed (11). 
I valued size with landscape, but even that was parsed as an error (13).
The error in line 5 makes no sense to me,because it is just the 'opposite'of @page:right, with is parsed as no-error.


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Your comments are remarks are valuable for teaching-purposes. 
I thank you in advance.

Filip Van Eeckhoutte
teacher webauthoring, -styling and -engineering
Holland.