# Manual Object Tagging

Tags are the platform's lightweight labelling mechanism — apply them to tables, datasets, columns, and quality tests to drive faceted search, organise the catalog by domain or stage, and signal special handling (`PII`, `Important`, `Deprecated`).

This page is the **read-side canonical home** for tagging — how operators apply, browse, and filter by tags. The operator-mutating side (curate the tag vocabulary, set the Important flag, manage namespace-scoped tags) lives at [Management → Tags](/features/management.md).

## What tags are

A tag is an operator-curated label that can be attached to any data entity or to any individual column. Tags drive:

* **Discovery.** The Tag facet on [Search and Filtering](/features/data-discovery/search.md) is one of the seven catalog filters; selecting one or more tags narrows the search to entities carrying any of them.
* **Organisation.** Tags are how operators encode lightweight, cross-cutting groupings that do not justify their own [Data Entity Group](/features/data-discovery/groups-domains.md).
* **Catalog Overview surfacing.** The most-used tags surface as the **Top tags** chip strip on the Catalog Overview home page — one-click filter into the catalog.
* **Important-flag visibility.** A tag flagged as **Important** in [Management → Tags](/features/management.md) is rendered visually distinct on entity pages and result rows, surfacing high-priority labels (`PII`, `Restricted`, `Deprecated`) without requiring operators to scan every tag chip.

## Applying tags

Apply tags both to data assets as a whole and to individual columns of datasets.

![](/files/3r4fQBsjG3S6HpZxYNY4)

The same UI flow applies at both granularities — open the entity (or column) detail surface, click the tag-management control, and pick from the existing tag vocabulary or create a new tag inline.

The platform exposes three `TAG_*` RBAC permissions:

| Permission   | Action                                      |
| ------------ | ------------------------------------------- |
| `TAG_CREATE` | Create a new tag in the catalog vocabulary. |
| `TAG_UPDATE` | Edit a tag's name or its Important flag.    |
| `TAG_DELETE` | Remove a tag from the catalog vocabulary.   |

Plus the cross-cutting `TAG_ASSIGNMENT_UPDATED` activity-event marker emitted whenever tag assignments on an entity change. This is **not** an RBAC permission — it is an entry on the `ActivityEventType` enum, surfaced on the [Activity Feed](/features/active-platform-features/activity-feed.md) for the affected entity rather than gating who can mutate tags.

For the platform-wide permission catalog and how to compose roles around these permissions, see [Permissions](/configuration-and-deployment/enable-security/authorization/permissions.md).

## Tag-driven discovery

Once tags are applied, three discovery paths rely on them:

* [**Search → Tag facet**](/features/data-discovery/search.md) — multi-select filter; results match entities carrying any of the selected tags.
* **Catalog Overview → Top tags** — one-click chip strip filtering into the catalog by the most-used tags across the deployment, rendered on the home page.
* **Tag-based per-entity badges** — tags appear on entity detail pages and in search result rows; Important-flagged tags render visually distinct.

## Operator workflow

The full lifecycle of a tag splits across two surfaces by design:

1. **Author the vocabulary** — go to [Management → Tags](/features/management.md) to create the canonical tag list, set the Important flag where appropriate, and govern the vocabulary across teams.
2. **Apply tags** — on entity detail pages, attach tags from the curated vocabulary to specific entities and columns.
3. **Narrow searches** — use the Tag facet on the Catalog page to find tagged entities.

Cornerstone 5 holds — two surfaces for two distinct content types: Management → Tags is the *operator-mutating* canonical home for the vocabulary; this page is the *read-side* canonical home for applying and finding by tags.

## Where to next

* [Search and Filtering](/features/data-discovery/search.md) — where the Tag facet narrows the catalog.
* [Data Entity Groups & Domains](/features/data-discovery/groups-domains.md) — the heavier-weight grouping mechanism for related entities (datasets, transformers, quality tests).
* [Management](/features/management.md) — the operator-mutating side: tag vocabulary curation, Important flag, namespace scoping.
* [Permissions](/configuration-and-deployment/enable-security/authorization/permissions.md) — the platform-wide permission catalog, including the three `TAG_*` rows.


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