what does the term "Capacity in which acting" means in IRS forms?

Public Comments

1. Like if you are the executor for someone's estate, or the custodian on an UTMA account, or the trustee for a family trust, or power of attorney, that is your capacity. "Why are you filling out this form on behalf of someone else? Well, I'm the executor of his estate" That's what they want to know.
2. if you are signing for a minor, or for someone over whom you have signing authority .... the 'capacity in which acting' could be.....PARENT, POWER OF ATTORNEY, EXECUTOR etc.