Replace auto-inserted markdown duplicate banners with real duplicate banners [duplicate]

Question

Long, long ago, duplicate banners used to be mere markdown in the body of a post. Like, for example, revision 3 on this post

> **Possible Duplicate:**  
> [particle で　versus particle　と](https://japanese.stackexchange.com/questions/8107/particle-%e3%81%a7%e3%80%80versus-particle%e3%80%80%e3%81%a8)  

<!-- End of automatically inserted text -->

Nowadays, of course, duplicate banners are some separate thing - not part of the body of a post.

Would it be possible to convert markdown duplicate banners into real duplicate banners, either as part of some behind-the-scenes batch job, or as part of some magic that happens when one edits a duplicate post that has a markdown banner?

This would also fix this issue, I guess: Shouldn't the closed-as-duplicate banner update when the title of the target changes?.

(Why am I editing duplicate posts that are so old that they predate the current banner system? In this case, to force markdown to be re-baked following this change to the markdown parser: Markdown change: Intra-word emphasis now works. Unlike questions closed for other reasons, I think duplicates ought to be maintained - users may still come across them and find them useful for whatever reason.)

Answer 1

If no automated system is implemented, and you still want to rectify it, you could find them manually using:

SELECT TOP 100 id as [Post Link], *
FROM Posts
WHERE CreationDate < '2013-01-01'
    AND Posts.PostTypeId = 1
    AND Body LIKE '%Possible Duplicate:%'

^{Adapted from this query}

On Data SE.

Just change CreationDate to the date that they changed the system, or get rid of it altogether (make sure to also lose the AND after it).

If you cover 100 relatively quickly, it won't update on Data SE until they do the weekly data dump. To find more, select more than the top 100.