Adding sub screen to standard T-code

[sairam1308]

What is the process for adding sub screen to standard T-code?

[Sandra_Rossi]

The question is really imprecise. Do you mean adding custom screen fields, not sub screen? What is your exact requirement?

If it's the exact question from an interview, ask them to fix the question.

[RaymondGiuseppi]

SAP provided some subscreen area in many standard transaction, so customers can display their own custom subscreen in those transactions, mostly implementing BAdI or Customer Exit.

Could you reformulate your question, what was your exact requirement?