I mentioned this on the Praxis Behind the Obscure podcast, but it deserves attention for those of you who may be making you own Sigillum Dei Aemeth. Some of the online designs are incorrect.
The first and probably most important issue is the inclusion of the y/14 cell at the bottom of the outer ring. This is probably most problematic because not only did the Archangel Michael directly tell Dee elsewhere in the diaries to fix it, but also because this causes the sum of the outer ring plus one (which was to be added as directed by Michael) to add up to 440, not 441. 441 is equivalent to the word “Aemeth” or “truth,” while 440 is equivalent to “dead.”
The next problem is that the angel name Ized is sometimes listed as Izad. Review DuQuette’s Enochian Vision Magick to see how the angel names are derived from the associated table.
Finally, the letter Z to the left of the top of the pentagram should actually be an S, for the same reason as mentioned above. Dee apparently replaced the S with a Z based on phonetics, something he did elsewhere at least marginally at one point in his diaries.
Have I mentioned how indebted I am to the Phergoph site? You should check it out.