so I'm filling in a form and there are various options for marital status: e.g. single, married, divorced, civil partnership etc etc. So far, so uncontroversial. But "co-habiting" is listed as a marital status.

What's the thinking behind this? surely they should either rename the question "relationship status" or exclude the option "co-habiting" - right?

I guess there's an argument for "common-law" spouses.

It's not something I particularly care strongly about, but just wondered if anyone could explain.