Symptom

Some of the custom fields are not available in the 'Card Layout' configuration of boards.

Diagnosis

This happens when the Applicable Contexts for the custom field is not Global ('All Issue Types').

Solution

Check the application context for the custom field as follows:

1. Browse to JIRA Administration > System > Custom Fields.
2. For the specific custom field, click on the Cog icon and select 'Configure'.
3. Under the 'Default Configuration Scheme' section, click on 'Edit Configuration' for the Application Contexts.
4. From the section 'Choose applicable issue types', for 'Issue Types', select the value 'Any issue type'.
5. Press 'Modify' to save the configuration.