diff --git a/output/openapi/elasticsearch-openapi.json b/output/openapi/elasticsearch-openapi.json
index 692f131b29..6d0df5ab72 100644
--- a/output/openapi/elasticsearch-openapi.json
+++ b/output/openapi/elasticsearch-openapi.json
@@ -13699,7 +13699,7 @@
             "required": true,
             "deprecated": false,
             "schema": {
-              "$ref": "#/components/schemas/_types.IndexName"
+              "$ref": "#/components/schemas/_types.Indices"
             },
             "style": "simple"
           },
@@ -13825,7 +13825,7 @@
             "required": true,
             "deprecated": false,
             "schema": {
-              "$ref": "#/components/schemas/_types.IndexName"
+              "$ref": "#/components/schemas/_types.Indices"
             },
             "style": "simple"
           },
@@ -40392,7 +40392,7 @@
             "required": true,
             "deprecated": false,
             "schema": {
-              "$ref": "#/components/schemas/_types.Name"
+              "$ref": "#/components/schemas/_types.Names"
             },
             "style": "simple"
           }
@@ -46511,7 +46511,7 @@
             "required": true,
             "deprecated": false,
             "schema": {
-              "$ref": "#/components/schemas/_types.Name"
+              "$ref": "#/components/schemas/_types.Names"
             },
             "style": "simple"
           },
@@ -49177,7 +49177,7 @@
             "description": "If `format` is set to `delimited`, you can specify the column names in a comma-separated list.\nIf this parameter is not specified, the structure finder uses the column names from the header row of the text.\nIf the text does not have a header row, columns are named \"column1\", \"column2\", \"column3\", for example.",
             "deprecated": false,
             "schema": {
-              "type": "string"
+              "$ref": "#/components/schemas/_types.Names"
             },
             "style": "form"
           },
@@ -138889,7 +138889,17 @@
         "description": "A comma-separated list of filters to apply to the response.",
         "deprecated": false,
         "schema": {
-          "type": "string"
+          "oneOf": [
+            {
+              "type": "string"
+            },
+            {
+              "type": "array",
+              "items": {
+                "type": "string"
+              }
+            }
+          ]
         },
         "x-state": "Generally available; Added in 8.2.0",
         "style": "form"
@@ -139953,7 +139963,7 @@
         "required": true,
         "deprecated": false,
         "schema": {
-          "$ref": "#/components/schemas/_types.IndexName"
+          "$ref": "#/components/schemas/_types.Indices"
         },
         "style": "simple"
       },
@@ -145843,7 +145853,7 @@
         "description": "If the format is `delimited`, you can specify the column names in a comma-separated list.\nIf this parameter is not specified, the structure finder uses the column names from the header row of the text.\nIf the text does not have a header role, columns are named \"column1\", \"column2\", \"column3\", for example.",
         "deprecated": false,
         "schema": {
-          "type": "string"
+          "$ref": "#/components/schemas/_types.Names"
         },
         "style": "form"
       },
diff --git a/output/openapi/elasticsearch-serverless-openapi.json b/output/openapi/elasticsearch-serverless-openapi.json
index d921f60720..c5270082f4 100644
--- a/output/openapi/elasticsearch-serverless-openapi.json
+++ b/output/openapi/elasticsearch-serverless-openapi.json
@@ -7269,7 +7269,7 @@
             "required": true,
             "deprecated": false,
             "schema": {
-              "$ref": "#/components/schemas/_types.IndexName"
+              "$ref": "#/components/schemas/_types.Indices"
             },
             "style": "simple"
           },
@@ -7395,7 +7395,7 @@
             "required": true,
             "deprecated": false,
             "schema": {
-              "$ref": "#/components/schemas/_types.IndexName"
+              "$ref": "#/components/schemas/_types.Indices"
             },
             "style": "simple"
           },
@@ -85396,7 +85396,17 @@
         "description": "A comma-separated list of filters to apply to the response.",
         "deprecated": false,
         "schema": {
-          "type": "string"
+          "oneOf": [
+            {
+              "type": "string"
+            },
+            {
+              "type": "array",
+              "items": {
+                "type": "string"
+              }
+            }
+          ]
         },
         "x-state": "Generally available",
         "style": "form"
diff --git a/output/schema/schema.json b/output/schema/schema.json
index 923aee4294..d2efd13d73 100644
--- a/output/schema/schema.json
+++ b/output/schema/schema.json
@@ -29606,11 +29606,26 @@
           "name": "filters",
           "required": false,
           "type": {
-            "kind": "instance_of",
-            "type": {
-              "name": "string",
-              "namespace": "_builtins"
-            }
+            "kind": "union_of",
+            "items": [
+              {
+                "kind": "instance_of",
+                "type": {
+                  "name": "string",
+                  "namespace": "_builtins"
+                }
+              },
+              {
+                "kind": "array_of",
+                "value": {
+                  "kind": "instance_of",
+                  "type": {
+                    "name": "string",
+                    "namespace": "_builtins"
+                  }
+                }
+              }
+            ]
           }
         },
         {
@@ -153826,7 +153841,7 @@
           "type": {
             "kind": "instance_of",
             "type": {
-              "name": "IndexName",
+              "name": "Indices",
               "namespace": "_types"
             }
           }
@@ -156304,7 +156319,7 @@
           "type": {
             "kind": "instance_of",
             "type": {
-              "name": "IndexName",
+              "name": "Indices",
               "namespace": "_types"
             }
           }
@@ -167471,7 +167486,7 @@
           "type": {
             "kind": "instance_of",
             "type": {
-              "name": "IndexName",
+              "name": "Indices",
               "namespace": "_types"
             }
           }
@@ -241780,7 +241795,7 @@
           "type": {
             "kind": "instance_of",
             "type": {
-              "name": "Name",
+              "name": "Names",
               "namespace": "_types"
             }
           }
@@ -260015,7 +260030,7 @@
           "type": {
             "kind": "instance_of",
             "type": {
-              "name": "Name",
+              "name": "Names",
               "namespace": "_types"
             }
           }
@@ -266900,8 +266915,8 @@
           "type": {
             "kind": "instance_of",
             "type": {
-              "name": "string",
-              "namespace": "_builtins"
+              "name": "Names",
+              "namespace": "_types"
             }
           }
         },
@@ -267347,8 +267362,8 @@
           "type": {
             "kind": "instance_of",
             "type": {
-              "name": "string",
-              "namespace": "_builtins"
+              "name": "Names",
+              "namespace": "_types"
             }
           }
         },
diff --git a/output/typescript/types.ts b/output/typescript/types.ts
index 8c95fa5b9e..b3b894b7e9 100644
--- a/output/typescript/types.ts
+++ b/output/typescript/types.ts
@@ -358,7 +358,7 @@ export interface FieldCapsRequest extends RequestBase {
   fields?: Fields
   ignore_unavailable?: boolean
   include_unmapped?: boolean
-  filters?: string
+  filters?: string | string[]
   types?: string[]
   include_empty_fields?: boolean
   project_routing?: ProjectRouting
@@ -12379,7 +12379,7 @@ export interface IndicesAddBlockAddIndicesBlockStatus {
 }
 
 export interface IndicesAddBlockRequest extends RequestBase {
-  index: IndexName
+  index: Indices
   block: IndicesIndicesBlockOptions
   allow_no_indices?: boolean
   expand_wildcards?: ExpandWildcards
@@ -12577,7 +12577,7 @@ export interface IndicesDataStreamsStatsDataStreamsStatsItem {
 }
 
 export interface IndicesDataStreamsStatsRequest extends RequestBase {
-  name?: IndexName
+  name?: Indices
   expand_wildcards?: ExpandWildcards
 }
 
@@ -13519,7 +13519,7 @@ export interface IndicesRemoveBlockRemoveIndicesBlockStatus {
 }
 
 export interface IndicesRemoveBlockRequest extends RequestBase {
-  index: IndexName
+  index: Indices
   block: IndicesIndicesBlockOptions
   allow_no_indices?: boolean
   expand_wildcards?: ExpandWildcards
@@ -20536,7 +20536,7 @@ export interface SecurityClearApiKeyCacheResponse {
 }
 
 export interface SecurityClearCachedPrivilegesRequest extends RequestBase {
-  application: Name
+  application: Names
 }
 
 export interface SecurityClearCachedPrivilegesResponse {
@@ -21996,7 +21996,7 @@ export type SnapshotCreateRepositoryResponse = AcknowledgedResponseBase
 
 export interface SnapshotDeleteRequest extends RequestBase {
   repository: Name
-  snapshot: Name
+  snapshot: Names
   master_timeout?: Duration
   wait_for_completion?: boolean
 }
@@ -22563,7 +22563,7 @@ export interface TextStructureTopHit {
 }
 
 export interface TextStructureFindFieldStructureRequest extends RequestBase {
-  column_names?: string
+  column_names?: Names
   delimiter?: string
   documents_to_sample?: uint
   ecs_compatibility?: TextStructureEcsCompatibilityType
@@ -22598,7 +22598,7 @@ export interface TextStructureFindFieldStructureResponse {
 }
 
 export interface TextStructureFindMessageStructureRequest extends RequestBase {
-  column_names?: string
+  column_names?: Names
   delimiter?: string
   ecs_compatibility?: TextStructureEcsCompatibilityType
   explain?: boolean
diff --git a/specification/_global/field_caps/FieldCapabilitiesRequest.ts b/specification/_global/field_caps/FieldCapabilitiesRequest.ts
index 9fab39a69e..05d32711a4 100644
--- a/specification/_global/field_caps/FieldCapabilitiesRequest.ts
+++ b/specification/_global/field_caps/FieldCapabilitiesRequest.ts
@@ -91,7 +91,7 @@ export interface Request extends RequestBase {
      * @availability stack since=8.2.0
      * @availability serverless
      */
-    filters?: string
+    filters?: string | string[]
     /**
      * A comma-separated list of field types to include.
      * Any fields that do not match one of these types will be excluded from the results.
diff --git a/specification/_global/terms_enum/TermsEnumRequest.ts b/specification/_global/terms_enum/TermsEnumRequest.ts
index c2c8dbc10d..f63332be68 100644
--- a/specification/_global/terms_enum/TermsEnumRequest.ts
+++ b/specification/_global/terms_enum/TermsEnumRequest.ts
@@ -18,7 +18,7 @@
  */
 
 import { RequestBase } from '@_types/Base'
-import { Field, IndexName } from '@_types/common'
+import { Field, Indices } from '@_types/common'
 import { integer } from '@_types/Numeric'
 import { QueryContainer } from '@_types/query_dsl/abstractions'
 import { Duration } from '@_types/Time'
@@ -50,7 +50,7 @@ export interface Request extends RequestBase {
      * Wildcard (`*`) expressions are supported.
      * To search all data streams or indices, omit this parameter or use `*`  or `_all`.
      */
-    index: IndexName
+    index: Indices
   }
   body: {
     /** The string to match at the start of indexed terms. If not provided, all terms in the field are considered. */
diff --git a/specification/indices/add_block/IndicesAddBlockRequest.ts b/specification/indices/add_block/IndicesAddBlockRequest.ts
index ddf5a41795..f337360b7b 100644
--- a/specification/indices/add_block/IndicesAddBlockRequest.ts
+++ b/specification/indices/add_block/IndicesAddBlockRequest.ts
@@ -18,7 +18,7 @@
  */
 
 import { RequestBase } from '@_types/Base'
-import { ExpandWildcards, IndexName } from '@_types/common'
+import { ExpandWildcards, Indices } from '@_types/common'
 import { Duration } from '@_types/Time'
 import { IndicesBlockOptions } from '@indices/_types/IndexSettings'
 
@@ -46,7 +46,7 @@ export interface Request extends RequestBase {
      * To allow the adding of blocks to indices with `_all`, `*`, or other wildcard expressions, change the `action.destructive_requires_name` setting to `false`.
      * You can update this setting in the `elasticsearch.yml` file or by using the cluster update settings API.
      */
-    index: IndexName
+    index: Indices
     /**
      * The block type to add to the index.
      */
diff --git a/specification/indices/data_streams_stats/IndicesDataStreamsStatsRequest.ts b/specification/indices/data_streams_stats/IndicesDataStreamsStatsRequest.ts
index ec064fcd60..59b0661150 100644
--- a/specification/indices/data_streams_stats/IndicesDataStreamsStatsRequest.ts
+++ b/specification/indices/data_streams_stats/IndicesDataStreamsStatsRequest.ts
@@ -18,7 +18,7 @@
  */
 
 import { RequestBase } from '@_types/Base'
-import { ExpandWildcards, IndexName } from '@_types/common'
+import { ExpandWildcards, Indices } from '@_types/common'
 
 /**
  * Get data stream stats.
@@ -48,7 +48,7 @@ export interface Request extends RequestBase {
      * Wildcard expressions (`*`) are supported.
      * To target all data streams in a cluster, omit this parameter or use `*`.
      */
-    name?: IndexName
+    name?: Indices
   }
   query_parameters: {
     /**
diff --git a/specification/indices/remove_block/IndicesRemoveBlockRequest.ts b/specification/indices/remove_block/IndicesRemoveBlockRequest.ts
index 8f990fbb5f..9173bd1f70 100644
--- a/specification/indices/remove_block/IndicesRemoveBlockRequest.ts
+++ b/specification/indices/remove_block/IndicesRemoveBlockRequest.ts
@@ -18,7 +18,7 @@
  */
 
 import { RequestBase } from '@_types/Base'
-import { ExpandWildcards, IndexName } from '@_types/common'
+import { ExpandWildcards, Indices } from '@_types/common'
 import { Duration } from '@_types/Time'
 import { IndicesBlockOptions } from '@indices/_types/IndexSettings'
 
@@ -47,7 +47,7 @@ export interface Request extends RequestBase {
      * To allow the removal of blocks from indices with `_all`, `*`, or other wildcard expressions, change the `action.destructive_requires_name` setting to `false`.
      * You can update this setting in the `elasticsearch.yml` file or by using the cluster update settings API.
      */
-    index: IndexName
+    index: Indices
     /**
      * The block type to remove from the index.
      */
diff --git a/specification/security/clear_cached_privileges/SecurityClearCachedPrivilegesRequest.ts b/specification/security/clear_cached_privileges/SecurityClearCachedPrivilegesRequest.ts
index 8af7ee807d..fbf96c1eb2 100644
--- a/specification/security/clear_cached_privileges/SecurityClearCachedPrivilegesRequest.ts
+++ b/specification/security/clear_cached_privileges/SecurityClearCachedPrivilegesRequest.ts
@@ -18,7 +18,7 @@
  */
 
 import { RequestBase } from '@_types/Base'
-import { Name } from '@_types/common'
+import { Names } from '@_types/common'
 
 /**
  * Clear the privileges cache.
@@ -44,6 +44,6 @@ export interface Request extends RequestBase {
      * To clear all applications, use an asterism (`*`).
      * It does not support other wildcard patterns.
      */
-    application: Name
+    application: Names
   }
 }
diff --git a/specification/snapshot/delete/SnapshotDeleteRequest.ts b/specification/snapshot/delete/SnapshotDeleteRequest.ts
index 299dbf6fae..eae6112d9a 100644
--- a/specification/snapshot/delete/SnapshotDeleteRequest.ts
+++ b/specification/snapshot/delete/SnapshotDeleteRequest.ts
@@ -18,7 +18,7 @@
  */
 
 import { RequestBase } from '@_types/Base'
-import { Name } from '@_types/common'
+import { Name, Names } from '@_types/common'
 import { Duration } from '@_types/Time'
 
 /**
@@ -45,7 +45,7 @@ export interface Request extends RequestBase {
      * A comma-separated list of snapshot names to delete.
      * It also accepts wildcards (`*`).
      */
-    snapshot: Name
+    snapshot: Names
   }
   query_parameters: {
     /**
diff --git a/specification/text_structure/find_field_structure/FindFieldStructureRequest.ts b/specification/text_structure/find_field_structure/FindFieldStructureRequest.ts
index 7a8e56beaf..9d72a59c09 100644
--- a/specification/text_structure/find_field_structure/FindFieldStructureRequest.ts
+++ b/specification/text_structure/find_field_structure/FindFieldStructureRequest.ts
@@ -60,7 +60,7 @@ interface Request extends RequestBase {
      * If this parameter is not specified, the structure finder uses the column names from the header row of the text.
      * If the text does not have a header row, columns are named "column1", "column2", "column3", for example.
      */
-    column_names?: string
+    column_names?: string | string[]
     /**
      * If you have set `format` to `delimited`, you can specify the character used to delimit the values in each row.
      * Only a single character is supported; the delimiter cannot have multiple characters.
diff --git a/specification/text_structure/find_message_structure/FindMessageStructureRequest.ts b/specification/text_structure/find_message_structure/FindMessageStructureRequest.ts
index 8310002878..ecb109ccf4 100644
--- a/specification/text_structure/find_message_structure/FindMessageStructureRequest.ts
+++ b/specification/text_structure/find_message_structure/FindMessageStructureRequest.ts
@@ -59,7 +59,7 @@ interface Request extends RequestBase {
      * If this parameter is not specified, the structure finder uses the column names from the header row of the text.
      * If the text does not have a header role, columns are named "column1", "column2", "column3", for example.
      */
-    column_names?: string
+    column_names?: string | string[]
     /**
      * If you the format is `delimited`, you can specify the character used to delimit the values in each row.
      * Only a single character is supported; the delimiter cannot have multiple characters.