> ## Documentation Index
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> Use this file to discover all available pages before exploring further.

> System table containing information about all masking policies in the system.

# system.masking_policies

<h2 id="description">
  Description
</h2>

Contains information about all masking policies defined in the system.

Masking policies can only be created and applied in ClickHouse Cloud. In open-source builds the `system.masking_policies` table is always empty, but it is still present so that introspection queries such as `SHOW MASKING POLICIES` work and return an empty result instead of throwing.

<h2 id="columns">
  Columns
</h2>

* `name` ([String](/reference/data-types/string)) — Name of a masking policy. The full name format is `short_name ON database.table`.
* `short_name` ([String](/reference/data-types/string)) — Short name of a masking policy. For example, if the full name is `mask_email ON mydb.mytable`, the short name is `mask_email`.
* `database` ([String](/reference/data-types/string)) — Database name.
* `table` ([String](/reference/data-types/string)) — Table name.
* `id` ([UUID](/reference/data-types/uuid)) — Masking policy ID.
* `storage` ([String](/reference/data-types/string)) — Name of the directory where the masking policy is stored.
* `update_assignments` ([Nullable(String)](/reference/data-types/nullable)) — UPDATE assignments that define how data should be masked. For example: `email = '***masked***', phone = '***-***-****'`.
* `where_condition` ([Nullable(String)](/reference/data-types/nullable)) — Optional WHERE condition that specifies when the masking should be applied.
* `priority` ([Int64](/reference/data-types/int-uint)) — Priority for applying multiple masking policies. Higher priority policies are applied first. Default is 0.
* `apply_to_all` ([UInt8](/reference/data-types/int-uint)) — Shows whether the masking policy applies to all roles and/or users. 1 if true, 0 otherwise.
* `apply_to_list` ([Array(String)](/reference/data-types/array)) — List of the roles and/or users to which the masking policy is applied.
* `apply_to_except` ([Array(String)](/reference/data-types/array)) — The masking policy is applied to all roles and/or users except the listed ones. Only populated when `apply_to_all` is 1.