Custom DEBUG messages are subject to theCustom Log Settingsfilters. If the script logs against a custom category but that category is not active at DEBUG severity, the messages are filtered and will not appear in the in-memory request logging used during non-production debugging.
Salesforce states that custom DEBUG and INFO logging are disabled by default and are configured throughAdministration > Operations > Custom Log Settings. The root/category hierarchy determines which custom messages pass the logging filter.
Therefore, the developer should enable the applicable category at DEBUG level. There is no Site Preference or Global Preference checkbox named " Enable custom logging in Request Log " that replaces this logging-category configuration.
On non-production instances, debug-level custom output can participate in in-memory logging associated with request diagnostics without necessarily requiring persistent debug log files. This makes category configuration particularly important when using the Storefront Toolkit Request Log for focused troubleshooting.
Developers should restore less verbose settings after diagnosing the issue because broad DEBUG logging can produce large volumes of data and make important diagnostic messages harder to isolate.
Study Guide reference:Application Development — Custom Log Settings, DEBUG categories, Storefront Toolkit Request Log, in-memory logging, and custom logging filters.
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