Create features with <null> value in currently symbolized field
I have a situation where I am creating features that I am intentionally not adding to my unique values symbology - I want them in my all other values category, but it turns out this is impossible to do. When creating features, you have to select one of your existing symbology values. There is no <null> option, meaning I have to just select one and edit it after the fact, which creates a lot of room for human error (which I am prone to!)
Is it a best practice to create data with intentional <null> values? No, but for my purposes, it's just me using this data, and it's much less work than creating another symbol class, domain code, etc.
If you click on the blue arrow you can set your symbol class value to null and create a feature:
Yes, you'll get a warning because it can be disorienting to create a feature that you don't see because it isn't symbolized:
but you can do it. The example above was with graduated colors but if I try with unique values like you mention in your idea, and I have my symbology set to display <all other values> then it is less weird.
So it isn't impossible.
That is exactly what I wanted to do! You have to go to Manage Templates
Add the symbol for Null values:
Then just delete the other ones.
