operator should use the appropriate prosigns to correct any portion of the message. After transmission and after a receipt is obtained, a  service  or  abbreviated  service  message  should  be used to send any correction. When  errors  or  omissions  are  noted  by  the receiving operator, corrections or repetitions are to be obtained before  a  receipt  has  been  given  by  the appropriate  prosign,  or after a receipt has been given by a service or abbreviated service message. NOTE The prosign IMI cannot be used to request repetition after a receipt has been given. A service or abbreviated service message used to obtain repetitions or send corrections is normally assigned a precedence equal to that of the message to which it refers. Corrections sent without a request are preceded by the prosign C with appropriate identifying data where necessary,  and  transmitted  in  the  same  manner  as  those sent in answer to a request for repetitions, corrections, or  verifications. When   repetitions   of   portions   of   a   message containing the call are made, the original call must be repeated in such repetitions except when only one station was called originally. In   accomplishing   the   previously   mentioned procedures, use the prosigns AA, AB, WA, and WB. These prosigns are used in service or abbreviated service messages in conjunction with IMI, INT, C, J, and   some   operating   signals.   IMI   is   used   by communications personnel to obtain a repetition; J is used by an addressee to obtain a verification and repetition of the entire transmission. Examples: Message C3 DE F5 -P-231010Z  MAR  96 -FM F5 -TO C3 -INFO B3 GR9 BT SEAKY-YAMXZ-HINLP-MMIAP-YSBOU- QWJFD-LJGFX-VITZG-ILTVQ To request repetition of the last transmission, C3 would send: F5 DE C3 IMI K To request all before the text, C3 would send: F5 DE C3 IMI AB BT K F5 would send: C3 DE F5 AB BT-C3 DE F5 -P-231010Z MAR 96 -FM F5 -TO C3 -INFO B3 GR9 BT K To request repetition of all before TO, C3 would send: F5 DE C3 IMI AB TO K F5  would  send: C3 DE F5 AB TO C3 DE F5 -P-231010Z MAR 96 -FM F5 -TO K To request repetition of the eighth group, C3 would send: F5 DE C3 IMI 8 K F5 would send: C3 DE F5 8-VITZG 4-7