As per the title.
== Explanaion ==
=== Common steps ===
1) I accidentially mention Task X in Task Y
2) I realize that I made a mistake and
-- correct the mention to the Task Z which is the one I meant, or
-- remove the mention at all as I was speaking about my favourite tank
=== What happens ===
3) Task X still has record of the mention in Task Y
=== What I expect/desire ===
3) Task X has the mention in Task Y record removed