Can you have a multi-line comment a crontab
Can I use the C++/Java-style /* */ syntax to multi-line comments in the crontab file?
The only comment character allowed in a crontab file is #. So you need to do:
# This is line 1
# This is line 2
0 0 * * * /usr/bin/magiccronjob
Edit: I believe it's man 5 crontab to see the details about crontab syntax.