By reassigning transfer RNA (tRNA)/aminoacyl-tRNA synthetase pairs the codon specificity can be changed. McNulty harbors a grudge against his former commanders for reassigning him to the marine unit. Meade, realizing this, proposed reassigning Sedgwick to command in the Shenandoah Valley. After reassigning several Allied divisions from Italy, they also attacked southern France. In the past reassigning codons was mainly done on a limited scale. Caliph al-Mahdi () replaced Hisham with his brother Bistam, before reassigning the latter to Adharbayjan.