I don’t want to be too picky, but I wonder about the use of plural ‘s’ in for some of the symbol names.  I have attached a screenshot of the Therion Book page 24.

I think symbols such as ‘discs-pillars’ should instead be named ‘disc-pillars’.

But of course English being English there are exceptions to the pattern, such as ‘pillars-with-curtains’ and ‘stalactites-stalagmites’ which are probably OK.