CHAPTER 10
952
Document Interchange
The unique name is formed by appending an encoded form of the page set’s digi-
tal identifier string to the original name of the destination or field. The identifier
string must be encoded to remove characters that have special meaning in desti-
nations and fields. For example, since the period character (
.
) is used as the field
separator in interactive form field names, it must not appear in the identifier por-
tion of the unique name; it is therefore encoded internally as two bytes, 92 and
112, corresponding to the ASCII characters
\p
. Note that since the backslash
character (
\
) has special meaning for the syntax of string objects, it must be pre-
ceded by another backslash when written in the PDF file. For example, if the orig-
inal digital identifier string were
alpha . beta
it would be encoded internally as
alpha \ pbeta
and written in the PDF file as
( alpha \ \ pbeta )
Similarly, the null character (character code 0) is encoded internally as the two
bytes 92 and 48, corresponding to the ASCII characters
\0
. If the original digital
identifier string were
alphaØbeta
(where
Ø
denotes the null character), it would be encoded internally as
alpha \ 0beta
and written in the PDF file as
( alpha \ \ 0beta )
Finally, the backslash character itself is encoded internally as the two bytes 92 and
92, corresponding to the characters
\\
. In written form, each of these in turn
requires a preceding backslash. Thus, the digital identifier string
alpha \ beta
would be encoded internally as
alpha \ \ beta
and written in the PDF file as
( alpha \ \ \ \ beta )