# Preservation Compatibility Differs From Editing Parity ## Claim A tool can remain compatible with a shared data format by faithfully preserving structures it doesn't understand, without ever promising to let a user edit them. <!-- atomicity: 1 idea ✓ --> ## Scope & conditions - Holds when parsing, reassembly, and a reliable fallback (refuse-to-save rather than guess) are all dependable — the fallback is what makes preservation trustworthy instead of merely hopeful. - Breaks when even "safe" limited operations (generic text or image replacement) end up mutating markup the tool doesn't own, or when the handoff to the tool that does own it becomes unreliable or inaccessible. - Demonstrated in Minn Admin's WordPress editor: it tokenizes a post, verifies byte-identical reassembly is possible, edits only allowlisted simple blocks, and treats everything else as an untouched island rather than attempting to regenerate it. ## Evidence > [!quote] > A simple block carrying an attribute the serializer cannot reproduce from the DOM becomes an island instead of a silent data loss. The claim reframes "compatible" as a spectrum rather than a binary: display-only, preserve-only, constrained-edit, and full-edit are different, non-substitutable levels of support, and a tool advertising "supports Gutenberg blocks" without specifying which level is making an underspecified claim. ## Links - [[3. Resources/Literature Notes/Gutenberg Is Huge for a Reason]] — source literature note, §H1 - [[3. Resources/Permanent Notes/A Never-Build List Protects Product Identity]] — because extends: preservation-only scope is one instance of a tool declining a capability on purpose - [[3. Resources/MOCs/Open Source Governance MOC]] — applies-in: compatibility claims between a platform and a third-party client sharing its data format ## Tests / falsifiers - A fixture where a prose-only edit in the smaller editor loses or silently alters markup inside an "island" — would falsify the preservation guarantee. - A plugin update that invalidates an untouched island after the smaller editor saves the surrounding post — would show the preservation contract doesn't survive upstream changes. ## Maintenance - Last tended: 2026-08-16 - Next review: 2026-11-16 ## Source - [Gutenberg Is Huge for a Reason. That Does Not Mean Every Editor Has to Be.](3.%20Resources/Readwise/Articles/Gutenberg%20Is%20Huge%20for%20a%20Reason.%20That%20Does%20Not%20Mean%20Every%20Editor%20Has%20to%20Be..md) — describes Minn Admin's tokenize/verify/allowlist/island pipeline.