ArcGIS Online allows you to set a property for an item in your contents to protect it from deletion. To delete an item with this property set means you have to manually turn it off then delete it.
I would like to see such a property on all datasets (e.g. FeatureClasses, Tables, Raster etc.) in a file geodatabase. This would stop you overwriting or deleting the dataset until you have ticked the property setting off.
Why would I ever want to do this? As a developer I create tools for automating geoprocessing. There is a law of diminishing returns in that as one develops tools you start discovering all the pathological cases in your data which require ever elaborate code to fix them. At some point it is quicker to edit those last few features. As soon as you do that the dataset becomes bespoke and not a final repeatable output from your tool. It is these cases I would like to be able to flag a dataset, just like in AGOL, as delete protected. This would stop me firing up that tool and overwriting any bespoke editing I may have done and forgotten about.
Anyone working up tools/models that do 99% of the data but fail on that last 1% where a manual intervention is required would see the benefit of being able to flag a dataset as delete protected to maintain it as a bespoke one time edited version.