Like you, I don't mind being called "Mr.", but the problem is that my sister would very much prefer not to put "Miss" (and not to lie) because it results in und

Like you, I don't mind being called "Mr.", but the problem is that my sister would very much prefer not to put "Miss" (and not to lie) because it results in undesired advances, and my wife would also prefer to not put "Mrs." because it results in discrimination for the opposite reason, and because it results in people asking to talk to me instead. At the same time, you can't drop it entirely, because my aunt will complain loudly if she's not allowed to put the "Dr." honorific that's very important to her identity in a title field. I agree with the recommendation that it's best just to have a big name field and allow users to be "Dr. Firstname Lastname" if they want that, or "Firstname Lastname" if they don't want a title, or "Englishname Surname Givename" if they want that. The push-back usually becomes that you can't trivially parse it a single name field later to use part of the name conversationally as if you know the person closely and send them spam with "Hey <nickname>, we haven't heard from you in a while, did you know that we now offer blah?". Instead, be honest, if you can't even take the time to understand the name syntax of an entire country, you don't know that user closely.