Following a meeting of the WBF Management Committee, Law 26B has been amended.
Law 26B now reads:
When an offending player’s call is withdrawn and it is not replaced by a comparable call, then if he becomes a defender declarer may, at the offender’s partner’s first turn to lead (which may be the opening lead) prohibit offender’s partner from leading any (one) suit which has not been specified in the legal auction by the offender. Such prohibition continues for as long as the offender’s partner retains the lead.
We would suggest making a permanent change in your new law book. The alteration can be easily made with a pen, or you can print this document, cut it to a sensible size, and affix it in your book at the top of page 53.