Declaration of Severance of Common-Law relationship?

[Ludovick]

Could anyone explain what is 'Declaration of Severance of Common-Law relationship' means or what it requires? It is on IMM5443 Document checklist. I've been in a relation from 1999-2004. I lived with my ex-gf for 5 years, but we had no children and no assets, no car, etc.

Do I have to provide any proof that this relation is over? I mean it's been 7 years that it's over, I don't even know where she lives now.