How to use hidden fields in eForm contact form?

I'm using eForm.tpl for a contact form:

https://modx.com/extras/package/eform

Description says:

• Protection of hidden fields against tampering

I want to add hidden fields to prevent spambots from using form. How can I do this?

There is information in the docs, here

Quote from: iusemodx at May 03, 2017, 07:26 AM

There is information in the docs, here

"By default hidden fields are validated as a protection against tampering by comparing the input against the value set in the form template (much like the select, checkbox and radio fields) In some circumstances this may not be desirable however."

I want to use hidden field "by default" as a protection against tampering. How should I do this?


I think it's simple but I don't get it.

This may help