S E C T I O N H .3
1121
Implementation Notes
136. When scaling a button’s appearance to the bounds of an annotation, ver-
sions of Acrobat earlier than 6.0 always took into account the line width
used to draw the border, even when no border was being drawn. Begin-
ning with Acrobat 6.0, the
FB
entry in the icon fit dictionary (see Table
137. Acrobat renames fields by prepending a page number, a template name,
and an ordinal number to the field name. The ordinal number cor-
responds to the order in which the template is applied to a page, with 0
being the first template specified for the page. For example, if the first
template used on the fifth page has the name
Template
and has the
Rename
flag set to
true
, fields defined in that template are renamed by
prepending the character string
P5 . Template_0 .
to their field names.
138. Adobe Extreme® printing systems require that the
Rename
flag be
true
.
139. Acrobat 6.0 computes a byte range digest only when the signature dictio-
nary is referenced from a signature field. There is no byte range signature
(that is, there is only an object signature) for FDF file signatures and usage
rights signatures referenced from the
UR
entry of a permissions dictio-
nary. In Acrobat 7.0, byte range digests are also computed for usage rights
signatures referenced from the
UR3
entry of a permissions dictionary.
140. Acrobat 6.0 and later do not provide the
Changes
entry.
141. Acrobat 6.0 and 7.0 always generate
DigestValue
when creating MDP sig-
natures. Acrobat 6.0 requires the presence of
DigestValue
in order to vali-
date MDP signatures. Acrobat 7.0 does not use
DigestValue
but compares
the current and signed versions of the document.
142. Acrobat 6.0 requires a usage rights signature dictionary that is referenced
from the
UR
entry of the permissions dictionary in order to validate the
usage rights. Acrobat 7.0 supports both
UR
and
UR3
; it uses the
UR3
dic-
tionary if both are present. Adobe PDF generating applications that sup-
port PDF 1.6 and greater generate
UR
only for backwards compatibility
with Acrobat Reader 6.0.