There is a strange behavior around backlinks for the case when TICKET table has a column that is not in TICKETCHNG. A typical example would be a "description" field.

If description of a ticket references a check-in (or some other entity) then /info page for that check-in shows the corresponding ticket among the references. This works as intended.
However if the reference to the aforementioned check-in is removed from the later revision of the description then /info page of that check-in would nevertheless continue to show that ticket among the references.

Such behavior differs from the behavior of the wiki where (back)references are maintained in correspondence with the latest version of a wiki page.
I think that the current handling of backlinks from such tickets' fields is sort of a bug which should be fixed.

Please share your opinion.

However if the reference to the aforementioned check-in is removed from the later revision of the description ...

Is that something which really happens in practice or is it a hypothetical situation?

I think that the current handling of backlinks from such tickets' fields is sort of a bug which should be fixed.

Agreed, but if it's only a hypothetical corner case problem then it might not be worth the effort of fixing. The backlink code is completely foreign to me, so i cannot estimate whether it would be trivial to fix or not.

Is that something which really happens in practice ... ?

For the time being, it's more like a hypothetical situation.
I've got a clue about it while studying the source-code some time ago.

... not be worth the effort of fixing

Agree. However it is important to know if it is considered as a bug or a feature. It is related to another issue where I'm still in limbo about which of the two routes is better.

The backlink code is completely foreign to me

I may be able to fix that myself. There's no hurry.