[sf-lug] fstab problem

[Alex Kleider]

Platform:
   Raspberry Pi 3 running latest image of raspian.

A /mnt/Rachel directory has been created.

The following line:
     LABEL=Rachel /mnt/Rachel ext4 defaults 0 0
has been added to the /etc/fstab file assuming that it could do no harm 
and would make it easier for me to mount an sd card where I wanted.

The problem now is that if I try to boot without that device connected I 
get a
     a start job is running for dev-disk-by...
notice and the system boots into "Emergency mode".

Is there an option I can add to the /etc/fstab entry that would allow 
the boot process to proceed normally even when there is no "Rachel" 
labelled device attached?

Thanks in advance.
Alex