Field glossary
Every GEOMETRY payload carries numeric fields ending in_no. Some are traditional numbers you already know. Others are internal identifiers. This page tells you which is which.
Internal catalog numbers
Fields ending in_no (system_no, planet_no, element_no, and similar) are GEOMETRY’s internal catalog and system identifiers. They exist for auditing, tracing, and troubleshooting, and are not part of the public contract — do not key caches, foreign keys, or application logic on them. Use names and slugs for durable integrations.
If you hit unexpected results, include the relevant _no values in your report — they let us reproduce your exact case immediately. See Support.
Tradition numbers vs catalog numbers
Tradition numbers are safe to display and reason about. Catalog numbers should be treated as opaque.
element_no means two different things
element_no appears in two lanes, and the value is read differently in each:
Classical elements have no atomic number, so
element_no is the one key present in both lanes. That is deliberate: element_no resolves for any element block, so you never need two code paths. Read it alongside element_name and treat the classical values as opaque.
The same applies to the element_no returned inside the celtic_ogham and norse_runes blocks — those are classical elements.
Zero means “not applicable”
Where a lookup has no match, or a concept does not apply to that date, GEOMETRY returns a typed placeholder rather thannull:
So
"card_no": 0 alongside "card_name": "none" means no card for this date in this system — not card number zero. Check for the placeholder, not for null.
One documented exception: day_ruler.norse.deity in get_day_card is null on Saturdays. Old Norse laugardagr means “bath day” and carries no deity, so the payload says so rather than inventing one.
Catalog numbers are non-negative. If you ever see a negative value in a _no field, that is a bug — please report it.