Heh... I was writing up a reply to Chrystal's post. But saw that both of you had posted while I was writing mine.

Hai, if you combine what you wrote with Chrystal's comment, look at it from this angle:
* The son have had to pretend that his mother is a free woman and his fathers wife for a decade.
* I was thinking that the father might own quite a few business that uses slaves. But he never deal with them directly, they just turn up as dry statistics on his business reports.
* The house hold slaves have been referred to as servants (serviteur in French?). Which, as an unimportant side note, happen to be a word that has its origin in the latin word for slave.
So he would be quite good to keep up the charade, and we also have this point to take into consideration:
* As his slave, the sister would probably be unable to appeal or take any legal action. But she might, as you previously mentioned, before she becomes a slave. So keeping up the charade would be the safest way to not rock the boat.
And what I was writing on

Just as you can't be expected to read the entire OOC thread looking for nuggets of information like that, equally, you can't expect the GM to remember to collect them together.
Well, I did read through the entire thread but could not recall that one.
Well, who said it had to be the GM's job?

As there is a wiki her on E. it would be possible to have an Q & A that everyone can update if I recall correctly. Then Haibane could take the information from there, if she want to update the intro-post or keeping an official canon Q & A for the game.

Things might still be overlooked. But more easy to catch and don't add as much work. It might even reduce the workload a bit.
One of the main reasons of my questions and arguments is also because I agree with this post:
I'd hope people would treat the game as having long term prospects and not play now and plan to drop out!
Better to find out if there is any incompatibilities beforehand.
But I do remember these two threads (my take is that it is IC threads and not the OOC thread; but as I'm not sure anymore, I find it best to have it clarified)
Players should only join group games if they have the time to fully commit to them. A character role that only means interaction with 1 or 2 other characters does not mean the character won't be fully interacting with the game world and that world is a construct that is constantly growing as a result of every post, therefore every player is required to read every post regardless of how distant it might be from their character's storyline.
I've been in too many games where scene A sets out some game-world facts only for other players in scene B to flat-out contradict them because they were not reading the posts in scene A. It looks poor and amateurish. I'm a perfectionist; I don't GM poor games 
As a general note I always require all players to read all posts in my group games. The benefits of consistency and continuity and imparting 'canon' information far outweigh the risks of metagaming and if the latter does happen, its quickly corrected with an OOC discussion and an edit.
Besides, for me, one of the main reasons I play in group games is so that I can read the posts of other writers and enjoy their skills and styles. It seems crazy not to when you have such a great opportunity to discover potential new RPing partners who you can then contact privately and perhaps set up a 1-on-1 game.
And to make a "compatibility check"

My preference is to write post that are 1-3 paragraph of lengths if someone can react to what I am writing. If it is a "solo scene", just describing something, or the only other player character present is bound and gagged; then a post can be quite a bit longer. I have seen some posts of that length in the group, so I assume they are acceptable despite most write significantly longer posts.
When it comes to reading posts of pony play and similar, my eyes glances over. So if reading all IC threads, to spot details, is an absolute rule, there might be a problem.