Most things we run into on a daily basis have abbreviations; numbers, symbols or shortened forms of words that are universal. Street signs, maps, gas station signs..but what happens when they're not universally understood? I have serious beef with elevator abbreviations. There's no legend, and I'm almost sure most people are just guessing what they mean. I'm thinking "L" most likely means 'lobby', but "G"? And the star probably has to do with braille, but who knows?
I don't care who you are, getting into a small box that moves isn't comfortable for anyone, they should make the experience as stress free as possible and just write it out.