(ERROR/3) Undefined substitution referenced

Hello,

using html2rest to convert the attached test.html.txt results in a file containing a single line indented with 2 spaces:
title some text\\|test|.. |test| image:: test.jpg
and when I convert that file with rst2html and other converters from Debian's docutils 0.12+dfsg-1 I get:
test.rst:1: (ERROR/3) Undefined substitution referenced: "test".

thank you,
Daniele