I have quite a sizable article being written right now although it does go on a bit and is being in parallel with a document concerning iaido gradings so it's taking quite a looooooonnnngggg time.
In the meantime I decided to translate page 35 of the ZNKR Seitei Iaido Manual which covers "How to enter and leave the dojo: Direction of stepping and rotation". This wasn't translated in the current English version and I have to be honest, I am not sure of the purpose of this except when we all go and do our 8th dan embu in Hakone. If you watch videos of these embu then you might notice a slightly more elaborate style of entry to the dojo and carrying out reiho. I believe this is in harmony with this diagram shown below.
The link for the PDF of this drawing (which is better quality than the JPEG shown below) should be downloadable here: