DataClassification & Caption Field property

Hello Experts,

Can I get your expert comment on Data Classification and Caption property? 

1) DataClassification what value should I use while creating a new field? Do I need to leave as default value like ToBeClassified? 

2) Is "ToBeClassified"  going to be removed by MS??

3) Does Caption property is mandatory at table level? if so why it is not showing error or suggestion? If not then where you recommend to define this property while creating the field?

        field(21; "Barcode"; Code[20])
            DataClassification = ToBeClassified;
            Caption = 'Barcode';
Thank you