Difference between excluding fields and changing the display method to "<hidden>"? Saving space by dropping one of them?

- The hidden formatter for field and fieldgroups hides the output completely.

- The exclude checkbox in "Display fields" screens hides the field from full node view, but $FIELD_NAME_rendered variables are still available in node templates.

This post might need to be clarified, as the contradicting information is confusing.

Earl Grey seems to be correct, from what I see when using the Devel Module ...

1.) Exclude (checkbox) completely hides the whole variable and the display.
2.) Hidden (in the dropdown) simply hides the display but keeps the variable available in the node (Hidden is simply another "formatter", like the rest of the selection in the display drop down)

Please let us know.

i stumbled upon this- as far as i realized, setting "hidden" completely disables the rendering for that field.
that was very important to me because i just "excluded" some fields from teaser view but still got performance-issues because their field-templates got called and rendered the field (without adding it to $content).
so if you don't want to display a special field, it should be set to hidden i think...?

Format <Hidden>: not rendered + not printed
Exclude checkbox: rendered + not printed

I was going bunkers with this!!. Thanks for the tips.
I have to say this is not clear, and it´s a very basic function.

Hidden - that sounds like it´s there but you can´t see it, which is actually what "Exclude" is!!. It´s the wrong way around. Exclude seems to say it´s excluded from display (but available as a variable).
Come on, something hidden is there, but hidden...

Agree?

agree ;)

Everyone I know who is starting to learn Drupal confuses these options. Surely needs to be revised.

Whats the difference between rendered and printed?

I guess the key part id this:

Use the 'Exclude' checkbox to exclude an item from the $content value passed to the node template.