[pdftex] \pdfstartlink attributes

[silvio mercadante]

Hi listers,
this is my first post here... please be patient :-)

I'm trying to understand the attributes of the \pdfstartlink ...  
\pdfendlink environment.
The PDFTeX manual says (p.34) that "Additional attributes, which are  
explained in great detail in the PDF Reference, can be given via
⟨attr spec ⟩."
Well, I can't undertand what's written in PDF Reference at all!  (Ehm,  
needless to say, I'm not an expert of the PDF language...)

My needs are:
1. What's the syntax of the <attr spec>?
2. What are the possible attributes?
3. Some examples.

Al this to be able to customize the following TeX macro:

\def\elink#1#2{%
\leavevmode%
\begingroup\pdfstartlink%
attr{/BS<</Type/Border/S/S/W 1>>}%
user{/Subtype/Link/A<</Type/Action/S/URI/URI(#1)>>}%
\ignorespaces#2%
\pdfendlink\endgroup%
}



Many thanks in advance