SECTION 8.3
595
Page-Level Navigation
number tree (Section 3.8.6, “Number Trees”), each of whose keys is the page
index of the first page in a labeling range. The corresponding value is a
page label
dictionary
defining the labeling characteristics for the pages in that range. The
tree must include a value for page index 0. Table 8.10 shows the contents of a page
label dictionary. (See implementation note 76 in Appendix H.)
i
,
ii
,
iii
,
iv
,
1
,
2
,
3
,
A−8
,
A−9
, …
Example 8.5
1 0 obj
<< /Type /Catalog
/PageLabels << /Nums [ 0 << /S /r >>
4 << /S /D >>
7 << /S /D
/P ( A− )
/St 8
>>
]
>>
…
>>
endobj
% A number tree containing
% three page label dictionaries
TABLE 8.10 Entries in a page label dictionary
KEY
TYPE
VALUE
Type
name
name
(Optional)
The type of PDF object that this dictionary describes; if present, must be
PageLabel
for a page label dictionary.
(Optional)
The numbering style to be used for the numeric portion of each page label:
D
R
r
A
a
S
Decimal arabic numerals
Uppercase roman numerals
Lowercase roman numerals
Uppercase letters (
A
to
Z
for the first 26 pages,
AA
to
ZZ
for the next 26, and so on)
Lowercase letters (
a
to
z
for the first 26 pages,
aa
to
zz
for the next 26, and so on)
There is no default numbering style; if no
S
entry is present, page labels consist solely of a
label prefix with no numeric portion. For example, if the
P
entry (below) specifies the la-
bel prefix
Contents
, each page is simply labeled
Contents
with no page number. (If the
P
entry is also missing or empty, the page label is an empty string.)