How to know which fields are custom fields in Portal 2.0

Yes! If the allowCustom option is set to true, users have the ability to add custom fields that are not defined in the data template. All custom fields are stored under the `$custom` object as a key-value pair. If you have a custom field called `ip_address`, for example, the `$custom` object might look something like this:

[
    {
        "id": "12",
        "name": "Taylor",
        "failure-note": "Avon",
        "$custom": {
            "ip_address": "192.452.243.214"
        },
        "sign": "Ooze",
        "shield-color": "Red"
    }
]