What did the abbreviation "RMS" stand for in the RMS Titanic in 1912?

RMS stands for Royal Mail Ship, indicating that the vessel was contracted to carry mail for the British Royal Mail. The Titanic had dedicated mail rooms and postal clerks aboard; carrying the mail was prestigious and helped subsidize passenger liners, giving them priority in some port services. Remember it by contrasting prefixes: HMS is a naval warship (His/Her Majesty’s Ship), while RMS is a civilian liner carrying Royal Mail—M for Mail. The Titanic wasn’t just a luxury liner; it was part of an international communication network, transporting thousands of mailbags alongside passengers. All five postal clerks aboard worked to save the mail until the end, and none survived, underscoring how central the mail service was to such ships.