The Central Register is customisable so you can remove columns you don't require. The Central Register is accessed through Admin > Personnel > Central Register.
Click on "Manage Data Items" near the top of the page.
Each option in the Central Register has an edit button in that row which is a pencil icon (shown below highlighted in yellow) and next to this, a bin icon to delete that option to completely.
Please note - if the delete icon is greyed out this column has been used, therefore you can not remove this.
You can either remove the information that is in this column, if it was entered by mistake (by clicking on the data in the table and clicking the bin icon).
Alternatively you can click the little eye icon in Manage Data Items to just "hide" the column, so data can't be added into it, but the original data is still there - simply click the eye icon again to unhide this.
More information on the Central Register can be found here.