I'm getting this naming convention from the BBeBXylog (LRS) specification:
http://www.y-adagio.com/public/commi...0_1017e_DC.pdf
As well as from some previous work that had been done with reverse engineering the LRF format:
http://www.sven.de/librie/Librie/LrfTag
kovidgoyal also uses the these terms in his code -- but for some reason, Python and I just don't grok each other and his libprs code base hasn't revealed to me what exactly they are and how to produce them.
If my pet project works out, I'll have a set of tools for going from LRF to LRS (XML) and LRS to LRF. The work I'm doing is in C#, and currently successfully decompiles very simple documents from LRF to LRS. This will let me then use XSLT to transform various XML stuff that I have to LRS, then to LRF, with a very high degree of control on the final formatting.