The |test_espace_prive filter is used to determine whether the page is displayed from private or public area.
For example, you may want to display a different block depending on whether the page is called up from private or public area:
[(#REM|test_prive_space|oui)<INCLURE{background=prive_block}>]
[(#REM|test_prive_space|non)<INCLURE{bottom=public_block}>]
Here, we apply the filter to the #REM tag, which prevents any hypothetical display of information linked to another tag.