The appeal, referred to as the "appellant's statement," shall be in writing and shall be signed by the appellant or his or her attorney. The appellant's statement need not be in any particular form but shall describe the retirement system manager's decision appealed from and shall state with reasonable specificity the bases for the appeal. Within thirty (30) calendar days of service of a copy of the appellant's statement, the respondent may file a statement with the retirement system manager stating with reasonable specificity the grounds upon which the respondent bases his or her objection to the appeal, but failure to file such statement shall not affect respondent's right to oppose said appeal. Such statement shall be referred to as the "respondent's statement. Such statements may be amended or supplemented at such times and upon such terms as the hearing officer or commission deem just. (Prior code § 34.14.1402)