Maintenance of Call Book pauses adjudication where identical issues are pending on appeal, requiring supervisory transfer and notice. Maintenance of a call book is required to defer adjudication of Show Cause Notices where identical issues are pending on appeal or where injunctions stay decision-making; SCNs under Sections 73(1) and 74(1) must be transferred with supervisory approval and taxpayers notified. Cases are to be restored to adjudication when controlling grounds cease or appellate decisions attain finality without further approval. Offices must keep a prescribed call book format, update it, and submit to monthly supervisory review, with each file verified rather than relying on statistical abstracts.