|Yeah, if you don't know (or are not sure). But I find it difficult to refer to a "Mary" or "Rosalyn" as a "he" in a reply - in situations where I know for sure (at least 99.9%) that the reply goes to a girl. When a poster identifies herself as "Mary", I consider the gender explicitly stated.
The reason why I asked is that "Joanna" as I know it is just as feminine as Mary or Rosalyn. So my question was not primarily about Internet gender conventions, but about this specific name in particular: Is the name Joanna given to boys - in Israel (like the Joanna starting this thread), or in other cultures?
I have argued myself for accepting role designations that for historical reasons are gender specific, as being gender neutral today. E.g. I have no problems accepting male midwives or cleaning ladies. But those are roles, not specific individuals. When I refer to individual persons where the gender is known, I find it strange to refer to the opposite gender. If I were to refer to one specific male midwife, I would never refer to him as "she".
Finish language has a traditional neutral gender reference merging "him" and "her". It is slowly being accepted in Swedish, and I have seen it in Norwegian as well: "hen" as as common term for "han" and "hun". I applaud that development.
Yet, I think it is OK that people call me a "coffee hag" (kaffekjerring) - a dialect expression for a person addicted to coffee. At one national congress, people from the south of Norway refused to believe that we have male hags in mid Norway. I had to get support from others from my district to confirm it. (This was in a discussion whether we should replace the gender specific term "formann" with the gender neutral "leder", where I argued that this is a role description, not a person description.)