Official UMB rules tend to be rather poor translations from French, the original being written when FDR was in the White House. Maybe that's a project we'll have to take on. What I did find was an old explanation of the balkline terms and announcements by the ref I wrote many moons ago. Maybe it'll help you out a bit.
First, here are the basic calls:
entree = both object balls are now in the same balk
dedans = both object balls are now in the same balk for the second time
a cheval = the object balls are (just) on different sides of the relevant line
This last call is 1) to reassure the player that he is not in trouble, and he does not need to walk around the table to check
2) to let the spectators know what the position is.
Now as you now, the same rules apply for the anchors, the little boxes drawn where the balkline meets the rail. So the two object balls can be entree or dedans for both the balk and the anchor.
These are the possible calls, with the balk position always called first, then the anchor position if there is one:
1) entree partout (which is the term used to describe entree et entree), the balls are in both the balk and the anchor, for the first time
2) entree dedans (entree et dedans, but the et is dropped for convenience), the balls are in the balk for the first time, in the anchor for the second time
3) dedans entree (the balls are in the balk for the second time, in the anchor for the first time)
4) dedans partout, the balls are in both the balk and the anchor for the second time
And then of course, there is a variety of calls with the reassuring "a cheval" , such as entree a cheval (you are entree for the balk and one ball is just out of the anchor), or a cheval dedans (you are not in the balk but you are in the anchor for the second time)
You will now have no trouble figuring out what a cheval partout means.
The referee is also expected to announce “libre” if the balls are extremely close but not touching. This, again, is for the benefit of the spectators and the opponent as much as it is for the player. So at the end of a match, a situation may occur where the referee is expected to say:
“ Two hundred and ninety-eight, dedans a cheval, playing for two, libre". You don't become a balkline referee overnight, this is a serious skill.
The above terms refer to 47/2 and 71/2. In case of balkline 47/1, there is no “entrée”, the balls are dedans as soon as they are in the same balk. There is no game called 71/1.
