A practitioner is considered to be "practicing before the IRS" with respect to all matters that are related to: $($i$)$ a presentation to the IRS on behalf of a taxpayer; and $($ii$)$ the taxpayer's:

a$.$

Rights, privileges, or liabilities under the United States Code.

b$.$

Rights, privileges, or liabilities under law and regulations administered by the IRS.

c$.$

Defense in response to a charge of tax evasion issued by the IRS.

d$.$

Claims for refunds of tax paid.