Astral, or star script, was used for hidden messages in the Labyrinth of Korsamm-Tiish. Wizards and others attempting the labyrinth could, if they had the secret, reveal inaccessible patterns pierced in the walls by pouring lamp-oil into apparently natural holes. The oil would flow into channels behind the piercings and when it was ignited its light would shine through the piercings, enabling them to be read.
The script was an alphabet based on the initial letters of the constellation or star from which or in which the asterism, or star-group, was taken. For example, the constellation Ywaeth, the Gall-Wasp, contained this asterism:
Accordingly, that pattern represented “yw”. The star Lruudem, the Claw, was found in this asterism of the constellation Tatsar, the Sieve:
Accordingly, that pattern represented “lr”. The full alphabet of oral consonants was as follows:
Nasal consonants were written using the star-glyph for the corresponding oral consonant plus the green planet Marath, 
, or red planet Ngwuur, 
or a comet, 
, as follows:
Vowels were written using the consonants y and w, plus their combinations:
Long vowels were represented by doubling.