[Typo3-dev] How does passthrough in tca work??

[Stig N. Jepsen]

> > There are two short examples on this page:
> >
http://typo3.org/documentation/document-library/doc_core_api/columns_fieldnam-8
> >
> > but I still can't seem to figure out the point :-)
>
>  The point is that you define a field you can't edit in the backend,
but
>  only through e.g. an extension (while you have other fields you
>  definitely want to edit there).
>
>  The key lies in this sentence:
>  [quote]
>  But still the update gets logged and the history/undo function will
>  work with such values.
>  [/quote]
>
>  That's the only purpose... I think.

So what can this field contain - what could the value be?

/Stig