| Value | Meaning |
|---|---|
| unspecified0 | The default. Equivalent to yes unless overridden by another UDA. |
| yes1 | always deserialize this field, fail if it is not present |
| opt2 | deserialize if found, but continue without error if it is missing |
| no3 | never deserialize this field |
Control the strictness with which a field is deserialized