What can you spell with the letters KNIGHT RIDDER? That’s the idea Merc columnist Mike Cassidy floated in a column about the 27-ton signs that remain atop the 17-story building that used to house the newspaper chain’s headquarters in San Jose. Combinations readers suggested included Hit Red Ink, Ink Died, KR Thing Died, Right Nerd Kid, Righted Drink and Dirt Herding.