The link https://iceberg.apache.org/concepts/catalog/ doesn't exist anymore.

Author: jbonofre

site/content/in-dev/unreleased/_index.md

@@ -56,15 +56,15 @@ or namespaces have been created yet for Catalog2 or Catalog3.
 In Polaris, you can create one or more catalog resources to organize Iceberg tables.
 
 Configure your catalog by setting values in the storage configuration for S3, Azure, or Google Cloud Storage. An Iceberg catalog enables a
-query engine to manage and organize tables. The catalog forms the first architectural layer in the [Apache Iceberg™ table specification](https://iceberg.apache.org/spec/#overview) and must support the following tasks:
+query engine to manage and organize tables. The catalog forms the first architectural layer in the [Apache Iceberg™ table specification](https://iceberg.apache.org/spec/#iceberg-table-spec) and must support the following tasks:
 
 - Storing the current metadata pointer for one or more Iceberg tables. A metadata pointer maps a table name to the location of that table's
   current metadata file.
 
 - Performing atomic operations so that you can update the current metadata pointer for a table to the metadata pointer of a new version of
   the table.
 
-To learn more about Iceberg catalogs, see the [Apache Iceberg™ documentation](https://iceberg.apache.org/concepts/catalog/).
+To learn more about Iceberg REST catalogs, see the [Apache Iceberg™ REST catalog specification](https://iceberg.apache.org/rest-catalog-spec/).
 
 #### Catalog types