Fair enough to use "Dr" or letters behind your name when dealing in a professional capacity, or workplace, but no place at all for any of that in "normal" life, such as booking an aircraft seat!
Then the same should go for all military ranks (Major, Captain and so on), all religious titles (Father, and Reverend and the like) as well as inherited and bestowed titles such as Lord, lady, Dame and the like.
*Why do people call themselves Mrs just because they got married?
Why is it ok to include marital status in a title but not an academic one?*
Exactly. My PhD is far more of an achievement than being married!
Red - I'm a biological woman, but I identify as 60Kg. :)