CHAPTER 8
742
Interactive Features
8.7.4 Legal Content Attestations
The PDF language provides a number of capabilities that can make the rendered
appearance of a PDF document vary. These capabilities could potentially be used
to construct a document that misleads the recipient of a document, intentionally
or unintentionally. These situations are relevant when considering the legal im-
plications of a signed PDF document.
Therefore, it is necessary to have a mechanism by which a document recipient
can determine whether the document can be trusted. The primary method is to
accept only documents that contain author signatures (one that has a
DocMDP
signature that defines what is permitted to change in a document; see “DocMDP”
When creating author signatures, applications should also create a
legal attesta-
tion dictionary,
whose entries are shown in Table 8.108. This dictionary is the val-
ue of the
Legal
entry in the document catalog (see Table 3.25). Its entries specify
all content that may result in unexpected rendering of the document contents.
The author may provide further clarification of such content by means of the
Attestation
entry. Reviewers should establish for themselves that they trust the
author and contents of the document. In the case of a legal challenge to the docu-
ment, any questionable content can be reviewed in the context of the information
in this dictionary.
TABLE 8.108 Entries in a legal attestation dictionary
KEY
TYPE
VALUE
JavaScriptActions
integer
integer
integer
integer
integer
integer
(Optional)
The number of JavaScript actions found in the document (see
(Optional)
The number of launch actions found in the document (see
(Optional)
The number of URI actions found in the document (see “URI
(Optional)
The number of movie actions found in the document (see “Mov-
(Optional)
The number of sound actions found in the document (see
(Optional)
The number of hide actions found in the document (see “Hide
LaunchActions
URIActions
MovieActions
SoundActions
HideAnnotationActions