What does it mean to be inactive? I see Pigeonly (W15) on the list, but they are...

		atentaten 7 months ago \| parent \| context \| favorite \| on: YC Graveyard: 821 inactive Y Combinator startups What does it mean to be inactive? I see Pigeonly (W15) on the list, but they are still active as far as their website is concerned.