How can I find all inactive/invalid choice list values (values that show as blue) for a single field?

[ndt13]

We have a custom field on the incident table that was originally a string field with no choice list, but now a choice list exists.   Is there a way to query this field to return all of the items with invalid values for this field?   I would like to create a module under the Incident application menu for itil users to clean up their old incidents with these invalid values.

Thanks

[Brad Tilton]

You could just use the filter to do a Field - Is not one of - Select all of the fields. This should work because the only options it wil give you will be legitimate choices. Here's an example using category on incident:

[ndt13]

I tried this, but the choice list has grown to 700+ choices.   When I try to open an incident form from this list, the page remains blank and never opens the form.

How can I find all inactive/invalid choice list values (values that show as blue) for a single field...