# A ghost wiki excerpt after tag merge

My understanding was that when a tag B is made a synonym of tag A and merged with it, then if B had any tag wiki excerpt it would not be visible anywhere anymore.

However, this apparently did not happen after was made a merged synonym of :

The excerpt for [mixed-anova] is visible, despite it being merged (see https://stats.stackexchange.com/tags/synonyms to verify that it is merged i.e. has 0 threads in it ). Moreover, even though it is visible, there is no edit link on mouseover, making it impossible to edit or delete it. It is a ghost excerpt!

(For comparison, the screenshot shows the edit link for [meta-analysis-mixed-effects] which is a synonym but is not merged; I was mouseover-ing it when I did the screenshot. Cf. Can I find excerpt/Wiki of a tag that is now a synonym of another tag?).

1. Is it indeed a bug that the wiki excerpt is visible?
2. If not, then is it a bug that the edit link is absent?
3. If not, then how can one edit or delete that wiki excerpt?

I am guessing that if one knew the tag id, one could manually try to access the edit page like this one: https://stats.stackexchange.com/edit-tag-wiki/3799. But how to find out the tag id?

• I wanted to find the tag id by executing select * from Tags where TagName = 'mixed-anova' at data.stackexchange.com but this query returns zero results (as is the case for other merged tags too). The synonym mapping can be found like this: select * from TagSynonyms where SourceTagName = 'mixed-anova' but this table does not contain tag ids. Mar 6 '18 at 11:36
• This sounds like a question for sitewide-meta (meta.stackexchange), though it may already have been asked there in some form. Mar 6 '18 at 12:32
• @Glen_b I searched there and did not find an answer (what I did find seemed to confirm that the wiki of a merged tag should be gone). I reckoned that if it's a bug then it makes sense to raise it on the site where it occurred. Mar 6 '18 at 12:33
• OK, using select * from Posts where PostTypeId=4 order by LastEditDate desc query I was able to find post id of this tag wiki excerpt. It is 324506. So now I could go to stats.stackexchange.com/posts/XX/edit replacing XX with 324506 and delete the wiki excerpt. However, I am not going to do it (and please nobody do it!!) in order not to disturb the bug. This query select * from Tags where ExcerptPostId=324506 returns empty result so I don't understand how [mixed-anova] could possibly show this excerpt on the Tags page. Looks more and more like a bug. Mar 6 '18 at 13:02
• My guess is that it's cached in HTML form somewhere and the cache was not rebuilt during merge for some reason. Mar 6 '18 at 16:31
• since the sites should all be using the same code for this, it will almost surely be a site-wide bug rather than a site-specific one, which is why I suggested the broader meta. (Yes, the PtB will see it here, but I'd expect they'd see it quicker there) Mar 7 '18 at 1:10

The ghost wiki excerpt eventually disappeared, even though I am not sure if this happened on its own or was a result of something me or @gung did (see here).

I was not able to edit https://stats.stackexchange.com/posts/324506/edit -- presumably such "abandoned" posts are locked which makes sense. The apparent bug was not that this abandoned post could be seen through the above link but that it was displayed as a wiki exceprt on the Tags page. Well, it is not anymore.

Anyway, I will mark this as accepted.

When merging tags, the tag wiki (and excerpt) are transferred to the destination tag only if the destination tag does not already have a wiki. This behavior allows tags to be renamed via merging while avoiding the danger of potentially destroying a useful wiki.

After merging, the old tag still exists for a brief period - there are no questions in it, but the records are still around. After that's cleaned up, its wiki is considered "orphaned"; moderators have a handy list of these available in their toolbox, but if you're interested you can find them yourself in the Data Explorer.

• Thanks but this does not fully explain to me what happened here. The merged tags are forever displayed on the Tags page as tags with 0 questions. They never go away from there. However, they don't have any tag wiki excerpt displayed there. In this particular case, the merged tag had its old wiki excerpt visible on the Tags page for at least a week. Then at certain moment this wiki excerpt disappeared from the Tags page. Are you saying that this specific sequence of events is by design? Jul 18 '18 at 19:47
• The listing that remains is for the synonym; it just redirects to the main tag. Jul 18 '18 at 19:49
• Yes, I know. But as I said, normally there is no wiki excerpt shown but in this case there was and it persisted for days (perhaps even weeks). Jul 18 '18 at 19:50
• That is a shockingly long time for a tag to hang around; usually it would be minutes, no more than a day. Jul 18 '18 at 20:53