By its digital nature, Digital NOTAM data is an enabler for better data quality. Digital data can be checked automatically for compliance with the requirements to a much larger extent than the NOTAM text. This might be done by dedicated services, both for data providers and for data users.
When possible errors are detected on the data usage side, it is interesting to be able to capture the text/description of these errors in the Digital NOTAM encoding. The Event/annotation with purpose WARNING shall be used.
This allows such warnings to eventually be displayed to end users, for example as part of a pre-flight briefing or to automatically transmit the error message to the data originator, asking for clarifications.