Custom Fields

Hi All

I was surprised to find that each users custom fields carry over! I am setting up a database to be used as a group resource and needs to be accessed by lots of people who also have their own databases. I have three custom fields but if I look at this database from another users profile this custom field look different depending on how they have set them up. Is there any way I can lock the custom fields on the database or stop this happening?

Thanks in advance