This reports which specific ATM threshold-crossing alert condition, from a long list including ingress buffer overflow, invalid VPI/VCI, ATM DC full, and several buffer-level markers, was most recently declared on this card. This is the single object an admin polls to quickly identify which of the many possible TCA conditions just fired, without having to poll every individual threshold or alert object on the card separately to figure out which one changed. For example, cardATMTcaId returning ingressBufferOverfloeC(1) tells the admin immediately that the most recent alert was an ingress buffer overflow, without checking each of the dozen individual TCA threshold objects.