subject property
The subject line of the notification.
The subject line may not exceed 10,240 bytes. In notifications generated by this policy, the contents of the subject line after variable expansion will be truncated to 255 bytes or shorter at the latest UTF-8 character boundary. The 255-byte limit is recommended by this thread (https://stackoverflow.com/questions/1592291/what-is-the-email-subject-length-limit). It is both the limit imposed by some third-party ticketing products and it is common to define textual fields in databases as VARCHAR(255).The contents of the subject line can be templatized by using variables (https://cloud.google.com/monitoring/alerts/doc-variables). If this field is missing or empty, a default subject line will be generated.
Optional.
Implementation
core.String? subject;