If the column used for a custom category is an identifier, such as a Customer ID, you can define it as a custom key and it can be used to match keys across datasets.

Custom keys can be defined in two ways:

• By selecting a column and 'KEY' in the Import Wizard - Custom categories tab when importing a dataset, or
• By selecting 'Is Key' when assigning a column to a custom category during normalizing a dataset.

Note: The System automatically prefixes the word “Custom” to all custom keys in the published dataset. For example, the custom key Customer ID will appear as CustomCustomer ID.