The #REM tag is used to insert comments into the code of your template files:
[(#REM) This is a comment ]
The tag and it’s optional portion are purely and simply deleted when the template file is calculated by SPIP. [(#REM)] does not appear in the HTML code for the public site and therefore will not display anything.
However, it is important to remember the abnormal effects of the #REM tag: the optional part of the tag must not contain any loop, such as is written in the example below:
[(#REM) this is a test loop: don't display it!
<BOUCLE_a(ARTICLES){...}{0,1}> #ID_ARTICLE - #TITRE </BOUCLE_a>
]
will display (something like):
this is a test loop: don't display it! 18 - My article title