(a) A registrant must not violate any provision of the Act or this chapter.(b) A registrant must timely respond to the department's investigative requests including making a complete written answer to any complaint.(c) Registrants must inform the department within 30 days of any changes to their employment and change their registration as appropriate.(d) A registrant must not violate the property tax professional's Code of Ethics, referenced in §94.100, or aid or encourage another to violate the Code of Ethics.(e) A registrant must not engage in any practices that constitute acts of improper influence, conflict of interest, unfair treatment, discrimination, abuse of powers, or misuse of titles.(f) A registrant must be in compliance with any report issued by the Comptroller of Public Accounts under §5.102 of the Tax Code.(g) An appraisal registrant or assessor/collector must be certified in their field within five years of registration.(h) A collector registrant must be certified in their field within three years of registration.(i) A registrant may act in a purely private capacity regarding a personal tax matter so long as he does not use his official position to influence the outcome of such a dispute.