Yes, officially this is a documentation bug. From [the *Absent Fields* doc][1]: > Fields that are not always guaranteed to be set... are indicated in the per-type documentation. **Any discrepency(sic) between observed behavior and the documentation should be reported on Stack Apps.** (Emphasis added and note that "discrepancy" is mispellerized. ;) ) ---------- `notice` obviously should have the `may be absent` flag. -------------------------------------------------------- I eyeballed all of the other properties of [type question][2], as well as [type answer][3] and [type user][4]. I didn't spot any other obvious discrepancies with the `may be absent` flag. ---------- Re: > The notice type, that is a field of a question, appears to be optional, yet it is not marked as "may be absent"? Optional and `may be absent` are separate dimensions. - "Optional" -- means you must craft/use a custom filter to get the property. - "May be absent" -- means that even if called for by the filter, the property will still not be returned if the property's value is null for that particular question. [1]: https://api.stackexchange.com/docs/absent-fields [2]: https://api.stackexchange.com/docs/types/question [3]: https://api.stackexchange.com/docs/types/answer [4]: https://api.stackexchange.com/docs/types/user