BRAXTON: very carefully. The circumstances of your life are going to change in the next few years. You'll be sent into rehabilitation again, forced to retire, and it's all because of Voyager!
SEVEN: Captain I believe your future self is suffering from temporal psychosis.
BRAXTON: Well of course I am, you pedantic drone. The only way for me, for us, to recover is to obliterate Voyager from the timeline. That way, none of the events that caused this illness will have occurred.
JANEWAY: What events?
BRAXTON: Thirty years of exile on twentieth century Earth. The temporal inversion in the Takara sector! Three violations that I had to repair.
EMH: Fifteen years?
KIM: Give or take a few weeks.
EMH: Where are we?
CHAKOTAY: In the Takara sector, just outside the Alpha quadrant.
EMH: The crew?
KIM: Except for us, dead.
The DTI from Deep Space Nine is a 24th century institution.
The two versions of a 29th century Temporal Integrity Commission from Voyager in Future's End were both 29th century institution, it's unclear if the USS Relativity was form either of those timelines despite it's dedication plaque listing it as a member of the temporal Integrity Commission.
The MANY unnamed 31st century Time Cop factions from Enterprise all pretending to be the same guy, are many mirror crosstime 31st institutions.