If those are the most prominent things you find for that abbreviation, I have to start doubting Wikipedia. As a German seeing that abbreviation so freely used is always a little bit shocking.

Thanks, TIL!

Apparently the RMS prefix on the RMS Titanic stands for "royal mail steamer" as it was authorised to carry the post.

Here is a great video on the topic.

https://youtu.be/ZOXymrplqCg

Gilligan's Island lied to us all. The Minnow clearly wasn't a steamer...