{merged} or {closed} markers for merged questions

Question

^{I had to use {x} in the title, because I'm not allowed to use [x] (especially not [closed]):}

^{Oops! Your question couldn't be submitted because:}

• ^{title can't include the closed marker.}
• ^{title contains a [tag] prefix; please use the tag field to enter tags instead.}

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Background

AFAICT, merged questions are essentially closed (as duplicate) with their answers moved to another, referenced question.

Different from closed questions, merged questions don't have a [closed] or similar marker in their title, even though nobody can post answers for them either.

Examples

Second topic here:

This topic:

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Request

Please add a marker similar to [closed] or [migrated] to merged questions, e.g. [merged]. It could also simply re-use [closed], because their result is very similar from a user's POV.