I had a smile, but I'm not sure I'd actually go out in the street wearing it, no.
Whilst I'm open about the fact I've got MS, it doesn't extend to broadcasting it to every random stranger.
Perhaps it's because I'm still lucky enough for it not to show, or at least to be able to delude myself that's the case.
But even if it did/does show, I'm not sure I want to wear a banner explaining it. I don't owe an explanation to people who don't know me, do I?
For emergency situations, where I might need to prove I have a disability, I do carry an "MS card" in my handbag. I've never had to flash it yet, but it's in case, at some point, I'm in the situation where someone asks: "Why does that fit young woman think she's entitled to a disabled seat?", or words to that effect...