The Navy publishes the Career Reenlistment Objectives (CREO) listing twice per year for sailors in the paygrades of E-1 through E-6. While the listing is intended to provide information about retraining possibilities, it also serves as a handy reference for promotion opportunities and for new applicants to determine whether or not the rating of their choice is likely to be available.
The Navy will usually favorably consider retraining requests for sailors serving in a CREO rating "2" or "3" who wish to retrain into a CREO rating "1." (Assuming the sailor is otherwise qualified for the new rating). Those serving in a CREO rating "3" who wish to retrain into a CREO rating "2" will be considered on a case-by-case basis.