I believe the cross bars are the horizon.

If it's the horizon why have so many represenatations, particularly in the Old Kingdom, got a knot in the middle?

I'm not trying to rehash the "sandal strap" discussion but any discussion of the Ankh has to address what the earliest Egyptian versions look like. I was intrigued to be told that there are older versions of the Ankh from elsewhere outside Egypt but I've not seen any yet.

I've also been surprised to find examples with two straight parts at the bottom, although these have been in illustrations, I'm looking for photographs.

I've always been interested in "exceptions" such as examples of the Djed pillar with five and not four divisions which exist.