This is something what is also lost here in the forum, but it's already in the CAR 6.1 and CAR 6.2:
Questions by Scott and Answers by Christian H. - at the HiG-Chat:
Scott, 10.07.2012 16:34:
Greetings to everybody here. This morning at CarcassonneCentral.com was published the long-awaited sixth edition of the Complete Annotated Rules for Carcassonne. Our new editor, Christopher Ober, has added some color-coded footnotes, of which the red ones indicate questions that have been raised in our community but no official answer has been sought, so I think now it's time to take care of that.
If a player has a follower and a builder on a road and then extends the road with a bridge, does that trigger the builder's double-turn or is that only when the road is extended by a tile?
Scott, 10.07.2012 16:39:
At the end of the game when the score for the King is being calculated, are castles included in the tally of the number of completed cities? (I suspect not, but somebody asked.)
Scott, 10.07.2012 16:46:
Can followers in the castle quarter of the City of Carcassonne (Count expansion) be moved to a castle (Bridges, Castles & Bazaars expansion)?
Christian H., 10.07.2012 23:58:
Hi Scott,
I'll answer your questions:
1) A castle isn't a city. It is a new area. So it doesn't count for the City of Carcassonne (town-quarter Castle) and not for the King-Tile.
2) The Builder-Turn will be triggered by increasing the Area. This means by a tile, by the bridge, by placing the tunnel-marker. The Dragon eats the Meeples on the Bridge, too.
There isn't a difference between a wooden bridge placed by a player and a printed bridge like at the following tiles (see Link "Plaettchenliste" in the Infobox above on this site): TA (bridge over city), HB (bridge over road), GFluss4 and GFluss5. Bridges are handled as roads.
Yours sincerely
Christian