[Koha] item type message about summary

[Nicole Engard]

On the Item Type admin page there is a box for 'summary' and under
that box it says

'Enter a summary that will overwrite the default one in search results
lists. Example, for a website itemtype :
<a href="[856u]">open site</a> will show the link just below the title'

I am wondering if anyone uses the summary on item types and what this
message means.  Why would I have a URL for an item type? Aren't the
URLs on the bibs and items themselves? I'm wondering if this is a
carry over from a much older version and is even necessary anymore. If
it is necessary can I have a more detailed explanation that I can put
in the manual please?

Thanks
Nicole