Re: CFC: null id values in ActivityPub objects

This erratum would break object portability. 

https://helge.codeberg.page/fep/fep/ef61/

Emelia

> On 28. Nov 2025, at 19:08, Evan Prodromou <evanp@socialwebfoundation.org> wrote:
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> Issue 476 on ActivityPub notes that the null value is not a valid JSON-LD property value, especially for IDs:
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> https://github.com/w3c/activitypub/issues/476
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> To correct this problem, there is a new erratum on the document:
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> Section 3.1 "Object identifiers", says in part that "identifiers must fall into one of the following groups: [...] An ID explicitly specified as the JSON null object, which implies an anonymous object (a part of its parent context)". However, Activity Streams 2.0 objects must be formatted as compacted JSON-LD objects, where `null` is not a meaningful property value, including for `id`. One solution is to simply leave the `id` property unspecified: ActivityPub extends this requirement; all objects distributed by the ActivityPub protocol MUST have unique global identifiers, unless they are intentionally transient or anonymous, in which case the identifier MAY be omitted. If present, the identifiers MUST be publicly dereferencable URIs, such as HTTPS URIs, with their authority belonging to that of their originating server. (Publicly facing content SHOULD use HTTPS URIs).
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> This is a call for consensus on adding this erratum. If there are no objections by 12 Dec 2025 anywhere on earth end of day, I will add this erratum to the errata for ActivityPub and apply the change to the editor's draft.
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> To object, reply to this thread or comment on GitHub.
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> Thanks,
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> Evan
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