Unicode has had this data field since 1998, yet there has been virtually no information online to explain the details. All you have are a lot of characters with a phonetic transcription.
I’ve recently bought Hugh Stimson’s Fifty Five Tang Poems which has an short explanation on his reconstruction. It has helped me to use the data available to write out an explanation of it for online use.
I’ve also included the entire kTang data for reference. As it is a fairly long essay with many tables, I’ve placed it on my website below.