In 1898 (14 years prior to the Titanic tragedy), Morgan Robertson wrote a novel called Futility. This fictitious novel was about the largest ship ever built hitting an iceberg in the Atlantic ocean on a cold April night. The fictional ship (named Titan) and the real ship Titanic were similar in design and their circumstances were remarkably alike. Both ships were labeled "unsinkable".
RMS stands for Royal Mail Steamer. RMS, in formal terms, means "Royal Merchant Ship". However, the dual meaning was also "Royal Mail Steamer", because the Titanic carried mail under the auspices of His Majesty's postal authorities. At that time, all ships, military and civilian, that were under the British flag carried the distinction of "R.M.S." This, in effect, gave the ship the protection of the British Crown. An attack on an R.M.S. was considered an attack on the crown and an act of war.
Originally, the Titanic's design only included 3 funnels (smokestacks). The aftmost funnel (towards stern) was added to make the Titanic look more impressive-it gave the feeling of "power and grace". It only functioned as an air vent.