Custom property with drop down value selection

[Mrock1]

I have been given a workbook (2016) that has an obvious custom property called Classification. It appears on the File Info properties list with a red asterisk next to it but I can't find it in the Custom Properties or Quick Parts. It also allows me to select a value from a dro down list on the File Info page with predefined values.

How was this property created, where is it stored and how can I edit the values list?

 

[Fluff]

Have a look here to see if it helps
https://www.ablebits.com/office-addins-blog/2014/01/22/excel-document-properties/

 

[Mrock1]

That’s just the point. These instructions show be usual way to see the various properties. However, the properties I’m seeing listed in the info page are not listed in the Custom properties at all. Hence my query.

It’s interesting that they also have the red asterisk next to them in the list and when you hover over the value field you see they are “required”. Presumably this is what causes the asterisk?? I just can’t find them anywhere to modify or delete them. I can only remove them by removing the meta data from the workbook which is overkill.

Frankly I’d really like to learn how to create properties that allow you to select from a list of values on the file info page and not within the document text.