Cascading Style Sheets - HTML and XHTML: The Definitive Guide - page 541

those margins. The default margins for the page box are not defined and
are browser dependent.
Finally, the marks property is used within the @page at-rule to create crop
and registration marks outside the page box on the target sheet. By de-
fault, no marks are printed. You may use one or both of the crop and
cross keywords to create crop marks and registration marks, respect-
ively, on the target print page.
8.4.13.2. Left, right, and first pages
In many printing applications, authors want different page layouts for
the first page of their document as well as differing formats for right and
left pages in double-sided documents. CSS2 accommodates all of these
cases using three pseudoclasses attached to the name of a page.
The :first pseudoclass applies the page format to the first page in a
document. Page-layout attributes specified in the :first page override
corresponding attributes in the general page layout. You can use the
:first pseudoclass in conjunction with a named page layout; the ap-
propriate first-page layout is applied if the first page of the document is
rendered using the named page.
In a similar fashion, the :left and :right pseudoclasses define left and
right page layouts for your document. Again, named pages can have left
and right variations. The browser automatically applies appropriate left
and right layouts to every page in the document, if such layouts exist.
You need not specify named pages to use any of these pseudoclasses.
Indeed, most documents do not do so. For example, if you use these
settings:
@page :first { margin-top : 3in }
@page :left { margin-left : 2in; margin-right : 1in }
@page :right { margin-left : 1in; margin-right : 2in }