gold lace between the two distinctive rings of half-inch braid which the ordinary lieutenant wore, and by 1877 he could wear it in undress uniform too. "Senior Lieutenant" had thus become a rank in all but name. From 1914, promotion to lieutenant-commander was automatic on reaching eight years' seniority as a lieutenant though, in around the year 2000, this has changed and the "half-stripe" is now achieved only by selection. Supply branch ratings had, in common with ratings from other branches of the Royal Navy, long been offered the opportunity of promotion from the lower deck. There were two avenues of receiving a commission. The Upper Yardman scheme (entering Britannia Royal Naval College (BRNC), Dartmouth, Devon, as a cadet or midshipman, under terms similar to those direct from civilian life) was open to those supply branch ratings under the age of about 25. Such ratings were called CW candidates, and they were specially reported on for selection to attend the Admiralty Interview Board before final selection for promotion and entry to BRNC. The second avenue of promotion from rating to commissioned officer was to the Special Duties (SD) List. Petty officers and chief petty officers could, with the approval of their commanding officer, become a CW candidate (an 'SD candidate') and such supply branch senior ratings were similarly specially reported on with a view to promotion to officer, generally between the ages of 28 and 35, though most were in their early 30s when promoted to acting sub-lieutenant on the Special Duties List. Unlike GL and SL (see below) officers, SD officers retained their former rating branch specialisation; for example the supply officer (cash) of a large warship or shore establishment would typically be a lieutenant (SD)(S)(W), the (W) indicating that he is a commissioned officer from the Writer branch of ratings. SD officers were, of course, promoted from all supply branches – writer (W), stores assistant/accountant (S) or (V), cook (CK), officer's steward/steward or caterer (CA). Once confirmed as a sub-lieutenant, an SD officer was promoted lieutenant after three years; promotion to lieutenant-commander (SD) was by selection and, from these, a very small number were promoted to commander from 1966 onwards. Retirement was generally compulsory at age 50. A few SD officers were further selected for transfer to the General List, seniority being adjusted on transfer, so as to level the promotion opportunities (generally these officers were earmarked as