10.25—Practice by former government employees, their partners and their associates.
        
        (1) 
        
            Assist means to act in such a
 way as to advise, furnish information to, or
 otherwise aid another person, directly, or
 indirectly.
    
    
        
        (2) 
        
            Government employee is an
 officer or employee of the United States or any
 agency of the United States, including a special
 Government employee as defined in 18 U.S.C.
 202(a), or of the District of Columbia, or of any
 State, or a member of Congress or of any State
 legislature.
    
    
        
        (3) 
        
            Member of a firm is a sole
 practitioner or an employee or associate thereof,
 or a partner, stockholder, associate, affiliate or
 employee of a partnership, joint venture,
 corporation, professional association or other
 affiliation of two or more practitioners who
 represent nongovernmental parties.
    
    
        
        (4) 
        
            Particular matter involving
 specific parties is defined at  5 CFR
 2637.201(c), or superseding post-employment
 regulations issued by the U.S. Office of
 Government Ethics.
    
    
        
        (5) 
        
            Rule includes Treasury
 regulations, whether issued or under preparation
 for issuance as notices of proposed rulemaking or
 as Treasury decisions, revenue rulings, and
 revenue procedures published in the Internal
 Revenue Bulletin (see  26 CFR 601.601(d)(2)(ii) (b )).
    
    
        
        (b) General rules—
        
        (1) 
         No former
Government employee may, subsequent to Government
employment, represent anyone in any matter
administered by the Internal Revenue Service if
the representation would violate 18 U.S.C. 207 or
any other laws of the United States.
    
    
        
        (2) 
         No former Government employee who
 personally and substantially participated in a
 particular matter involving specific parties may,
 subsequent to Government employment, represent or
 knowingly assist, in that particular matter, any
 person who is or was a specific party to that
 particular matter.
    
    
        
        (3) 
         A former Government employee who within a
 period of one year prior to the termination of
 Government employment had official responsibility
 for a particular matter involving specific parties
 may not, within two years after Government
 employment is ended, represent in that particular
 matter any person who is or was a specific party
 to that particular matter.
    
    
        
        (4) 
         No former Government employee may, within
 one year after Government employment is ended,
 communicate with or appear before, with the intent
 to influence, any employee of the Treasury
 Department in connection with the publication,
 withdrawal, amendment, modification, or
 interpretation of a rule the development of which
 the former Government employee participated in, or
 for which, within a period of one year prior to
 the termination of Government employment, the
 former government employee had official
 responsibility. This paragraph (b)(4) does not,
 however, preclude any former employee from
 appearing on one's own behalf or from representing
 a taxpayer before the Internal Revenue Service in
 connection with a particular matter involving
 specific parties involving the application or
 interpretation of a rule with respect to that
 particular matter, provided that the
 representation is otherwise consistent with the
 other provisions of this section and the former
 employee does not utilize or disclose any
 confidential information acquired by the former
 employee in the development of the rule.
    
    
        
        (c) Firm representation—
        
        (1) 
         No
member of a firm of which a former Government
employee is a member may represent or knowingly
assist a person who was or is a specific party in
any particular matter with respect to which the
restrictions of paragraph (b)(2) of this section
apply to the former Government employee, in that
particular matter, unless the firm isolates the
former Government employee in such a way to ensure
that the former Government employee cannot assist
in the representation.
    
    
        
        (2) 
         When isolation of a former Government
 employee is required under paragraph (c)(1) of
 this section, a statement affirming the fact of
 such isolation must be executed under oath by the
 former Government employee and by another member
 of the firm acting on behalf of the firm. The
 statement must clearly identify the firm, the
 former Government employee, and the particular
 matter(s) requiring isolation. The statement must
 be retained by the firm and, upon request,
 provided to the Director of the Office of
 Professional Responsibility.
    
    
        
        (d) Pending representation.
         The
 provisions of this regulation will govern practice
 by former Government employees, their partners and
 associates with respect to representation in
 particular matters involving specific parties
 where actual representation commenced before the
 effective date of this regulation