Currently, there are four cleanup commands that are included in the EzPublishMigrationBundle. It would be useful to document what they are doing, how to execute them and what issues they solve, so the developers will be able to easily find them if they encounter such issue.

• ezpublish:update:legacy_storage_clean_up_relation_type_eq_zero - created for EZP-27254. As the error happens only when using REST API, it can manifest itself after upgrading to v1 or v2.
• ezplatform:regenerate:legacy_storage_url_aliases - documented (a little) here: https://doc.ezplatform.com/en/1.7/guide/repository/#regenerating-url-aliases
• ezpublish:update:legacy_storage_fix_fields_always_available_flag - created for EZP-24882.
• ezpublish:update:legacy_storage_update_sort_keys - created for EZP-23924. Also mentioned in the upgrade doc here: https://github.com/ezsystems/ezpublish-kernel/blob/master/doc/upgrade/6.0.md#update-field-sort-keys-for-ezstring-and-ezobjectrelationlist-field-types

Additionally, it would be a good idea to link to these documented commands from the upgrade documentation page if the issues can manifest themselves after an upgrade.