When is an organism captive?

This is a subject that comes up again and again. Besides the links that cthawley provided, here are a few more:
Animals in Temporary Captivity - General - iNaturalist Community Forum
Should I be marking Ant Queen caught for ant keeping as Captive? - General - iNaturalist Community Forum
Do terrarium observations count as “captive”? - General - iNaturalist Community Forum