Save-time validation

The review panel is advisory. Save-time validation is the point where RedPen can actually stop something — and it is off until you turn it on.

Pro only. In Lite, RedPen never evaluates content on save.

Two settings, both off

Setting	Default	What it does
`checkOnSave`	`false`	Evaluate the element against its profile when it is saved.
`blockOnError`	`false`	Let an error-severity finding actually fail the save.

With checkOnSave on and blockOnError off, findings are recorded and surfaced as a notice on the entry, and everything still saves. That is the useful middle setting, and the one to start with.

Both default to off for the same reason: a plugin that starts refusing saves the moment it is installed generates a support ticket, not better content. Switching this on should be a decision someone makes on purpose, after they have seen what the rules actually flag on their site.

What is exempt

Even with both settings on, RedPen does not validate:

Drafts — the whole point of a draft is that it is not finished.
Revisions — already saved once; failing them retroactively is meaningless.
Propagating saves — the same content being copied to another site.
Resaves — resave/entries and similar bulk operations, which would otherwise turn into a wall of failures nobody can act on.
Disabled elements — not published, so not yet held to the standard.
Console requests — a queue job or a CLI resave must not be blocked by editorial rules. Use the console command for that instead, where the result is a report and an exit code rather than a crash.

Choosing what blocks

Only error severity can block, and no rule ships at error severity. To make one blocking, raise it in the profile — typically the accessibility rules, which are the ones with a consequence beyond taste:

accessibility.image-alt at error — no image ships without alt text.
accessibility.link-text at error — no “click here” ships.

Leave terminology and style at warning or notice. A writer who cannot publish because of a hedging adverb will find a way around the plugin, and then it is protecting nothing.

Editorial sign-off

Sign-off records who proofread an entry and when. It is cleared automatically when the content changes, so a stale sign-off cannot vouch for copy nobody has read. Pair it with a warning-level profile when you want a human gate rather than a mechanical one.