If this is a duplicate I appoligize, but looking for two-letter strings is quite hard in any search.

I'm looking for the meaning of tA tC and tP in the context of a mysql query. And in the spirit of "teaching a man how to fish" it would be great if you could point me in the right direction of where to find this info in the future.

Edit: The Query

$wpdb->get_row($wpdb->prepare("SELECT tA.* FROM ".AMYLITE_ADS." tA,
    ".AMYLITE_ADS_CAMPAIGNS." tC, ".AMYLITE_PACKAGES." tP
    WHERE tA.id=tC.ad_id AND tC.campaign_id=tP.campaign_id AND tP.zone_id=%d
    AND tP.date_end>CURDATE()
    GROUP BY tA.id ORDER BY RAND()", $zone->id));