Settings of LT31

[monamipierrot]

I opened this topic for posting about settings of current game LT31:

- If you know the big picture or some relevant details of it, please post. Please also copy&paste relevant discussion from ingame chats or IRC channels. To share your knowledge will be considered honourful. One may also want to compile all or part of this knowledge in separate threads/posts.
- If on the other hand you want to know about specific ones, please post a question here, but remember it could leak relevant hints about your nation. Before posting, please also remember to check if you can already find the answer in the server-side settings of your client settings window.

1st requests is from me.
I kindly ask administrators or knowledgeable players to write here:
1 - most important settings that can't be inferred from our clients (e.g. size of workable land for city, movement restriction, visibility range and borders calculation), expecially the ones which were different since last game, LT30.
2 - all those settings which the client may be wrong in displaying, if any.

Thanks!