OnAgainOffAgain relations - beyond celeb marriage: Org membership

The celebrity re-marriage example is interesting and real, but may look a
bit artificial or cornercase. A similarly structured situation is much more
common - membership of organizations.

For example one organization being a member of another.

https://www.wikidata.org/wiki/Q51698517 is the International Fact Checking
Network (IFCN). It has a notion of membership grounded in review of members
w.r.t. their official principles.

Verified signatories are e.g. https://www.wikidata.org/wiki/Q30325238 (Full
Fact). There are some organizations such as Snopes (
https://www.wikidata.org/wiki/Q2287154) who were once members (verified
signatories) but who are not currently.

Wikidata uses annotations on a https://www.wikidata.org/wiki/Property:P463
edge between IFCN and Snopes to give start/end times (
15 April 2017, 5 June 2019). It also points to evidence/source document.

As far as I know Snopes have only been members once, but if they were to
rejoin it seems Wikidata could accomodate the task of representing this.

Until I learn a better name for it that isn't too grandiose, I am calling
these "on again, off again" relationships, in honour of the celebrity
marriage/divorce usecase.

Dan

p.s. another example, not quite notable enough for Wikidata to record:
I (https://www.wikidata.org/entity/Q56641640) have twice been a member of
https://www.wikidata.org/wiki/Q7552326 (AISB - Society for the Study of
Artificial Intelligence and Simulation of Behaviour).  But then I have
multiple times lived in the U.K., or been in various restaurants; how do we
scope RDF-Star's applicability? Which of these are reasonable places it
could be used for time-scoped relationships?