# Page Data: Reserved paths

> Namespaces the system owns.

Glider documentation · Data · Web page: https://cgglider.com/docs/page-data/reserved/

Sections of this page: [Editing data](https://cgglider.com/docs/page-data.md) · [Paths](https://cgglider.com/docs/page-data/paths.md) · [The runtime store](https://cgglider.com/docs/page-data/store.md) · [Reserved paths](https://cgglider.com/docs/page-data/reserved.md) · [Keys view](https://cgglider.com/docs/page-data/keys-panel.md)

| Prefix | Owner | Meaning |
| --- | --- | --- |
| sys.hidden.<nodeId> | Reactions | A boolean written by a reaction's show / hide. It overrides the node's own hidden flag. |
| sys.slot.<nodeId>.<target> | Pollers | A folded poller field mapping — the value a feed paints into one component input. |
| sheets.<sheetId>.<tab>.<A1> | Sheets | The read-only projection of bound spreadsheet cells. |
| vars.<name> | Variables | The read-only projection of page Variables. Change them in the Variables tab; units may not write here. |

> **Warning:** Do not author these by hand. The sheets and vars keys are stripped from the Data tab's JSON view for exactly this reason — they are projected from the Sheets section and the Variables tab and rewritten on every change.