Functions of TAG 23E in MT101 format

Hi Experts,

Could you please let me know about Tag 23E. I would like get to know about tag 23E in MT101 format. I have some below queries :-

1. What is TAG 23E ?

2. What is the function of Tag 23E in MT101?

3. If require to change tag 23E then who is the responsible to change it ..... Whether by PI team or ABAP team ?

Thanks in advance for your prompt response.

Thanks & Regards,

Raj Kumar