[lug] Where's the "MASTER" crontab file?

[Bill Thoen]

When you issue a 'crontab -e' from an RH9 system does it copy your cron
table from /var/cron/ into a temporary file, invokes the default editor
with this and then replace the original file with the edited copy?

The reason I ask is because I want to make a daily backup of all the files 
relevant to my user account, and I want to know if /var/cron/bthoen is the 
file I need to save or if the "master" file (darkly mentioned in the 
crontab file header as in, thou shalt not edit this...) is actually 
somewhere else.

Thanks,

Bill Thoen