Both default variables and permanent custom variables can be excluded from your document(s) when you don't need them. If you are using an "offer" type document, then the excluded variables will appear at the bottom of the window when filling out the offer details and can be filled in for internal use only (this is optional and not mandatory).
Below, for example, the variables Sick Days, Offered Equity, etc were excluded from the offer document, so you can either fill them out for internal reference or just ignore them.
When information for internal reference is completed, it will appear on the candidate timeline under the offer letter details.
Note: It is not possible to delete permanent custom variables that have already been used.