Record Rules should allow access to any field of an Object
Record rules allow an object to be created and its fields to be set using one of a few options. Currently these options allow us to set a field:
- to a custom value
- to a connected value
- to a form value
The missing one is
- to a record value
The restriction that fields in the record must be on the form in order to be used is strange. At best it requires a clumsy workaround - you add a field to the form, just so that you can use it in this context; and use Display Rules to hide it. At second best, you have to a double workaround: some fields (such as auto-increment) can't be placed on an 'add' form; so then you have to add an 'Equation' field which references the auto-increment field to the Object, just so that you can add that 'gooseberry' Equation field to the form, and hide it in Display Rules, just so that you can reference the gooseberry field in the Record Rules. And at worst, neither of these workarounds is available - e.g. with a Text Formula field.
It seems particularly odd, since the "to a connected value" option allows you to use any field on the connected object - regardless of whether those fields are on a particular form or not.