- The Sign of the Bull by Jeanne Judson · (ss)
- The Sign of the Bull by Thomas McMorrow · (??)
- The Sign of the Christmas-Tree by Anna Steese Richardson · (ar)
- Sign of the Cobra by L. M. Hainer · (ss)
- Sign of the Cobra by Donald Millard · (ss)
- The Sign of the Cobra by Michael Gifford White · (sl)
- The Sign of the Covenant by Katharine Holland Brown · (ss)
- The Sign of the Crab by J. Aubrey Tyson · (na)
- The Sign of the Crimson Dagger: 77, Staine Street by [uncredited] · (ss)
- The Sign of the Crimson Dagger: Bonds of Hate! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: Enemies of Society by [uncredited] · (ss)
- The Sign of the Crimson Dagger: Fragments of Glass! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: Hidden Treasure! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: In His Own Trap! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: Out of the Depths! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: Rescued Evidence! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: Stranded by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Acid Test! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Cloud of Doom by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Coiners’ Lair by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Greed of Gold! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Home Wrecker by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Lure of the Footlights by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Man in Rags by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Mine of Doom by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Peril of the Deep by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Pillar of Fire by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Raiding Destroyer! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Repentance of Rufus Raynor by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Secret of the River! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Secret of the Shoal by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Stolen Play by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Street of Silence! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Tappings on the Wall! by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The Tinned Meat King by [uncredited] · (ss)
- The Sign of the Crimson Dagger: The White Prison by [uncredited] · (ss)
- Sign of the Crimson Mask by Norman A. Daniels · (na)
- Sign of the Crimson Mask by Frank Johnson · (na)
- Sign of the Crooked Cross by Philip Gibbs · (ss)
- The Sign of the Cross by L. B. Birdsall · (ss)
- The Sign of the Cross by Albert Dorrington · (ss)
- The Sign of the Cross by Russell Stanley Geronimo · (ss)
- The Sign of the Cross by James M. Hopper · (ss)
- The Sign of the Cross by Gene KoKayKo · (ss)
- The Sign of the Cross by John Geddie Macdonald · (vi)
- The Sign of the Cross. A Narrative Piece by John Swinton · (pm)
- The Sign of the Crossed Daggers by A. Donnelly Aitken · (ss)
- The Sign of the Cross: The Story of an Ancient Symbol by Leslie A. Shepard · (ar)
- The Sign of the Dagger by Beatrice Walsh · (nv)
- The Sign of the Dagger by [uncredited] · (sl)
- Sign of the Devildog by Roswell Brown · (ss)
- Sign of the Devildog by Jean Francis Webb · (ss)
- The Sign of the Dollar by [uncredited] · (ar)
- Sign of the Double-Cross by Pierre Louval · (ss)
- Sign of the Double Dragon by Jerry MacDougall · (ss)
- The Sign of the Double Swastika by [uncredited] · (n.)
- The Sign of the Dove by Allan Scott · (vi)
- The Sign of the Dragon by C. W. Armstrong · (ss)
- The Sign of the Dragon by Edwin Vernon Burkholder · (ss)
- Sign of the Dragon by C. M. Eddy, Jr. · (nv)
- The Sign of the Dragon by John Hunter · (na)
- The Sign of the Dragon by George Allan Moffatt · (ss)
- Sign of the Dragon by Paschal N. Strong · (ss)
- The Sign of the Dragon by Helen J. Taylor · (pm)
- The Sign of the Dragon-Fly by Glenn Lord · (ar)
- The Sign of the Eagle’s Claw by John Fortescue · (ss)
- The Sign of the Elephant God by S. A. Bridgman · (ss)
- The Sign of the Evening Lamp by Harriet Whitney Durbin · (pm)
- Sign of the Evil Eye by John D. Swain · (ss)
- The Sign of the Falling Leaf by Bertrand W. Sinclair · (ss)
- The Sign of the First Dollar by Leon Ware · (ss)
- The Sign of the Fishes by Thomas McMorrow · (??)
- The Sign of the Flaming Torch by Edwy Searles Brooks · (na)
- The Sign of the Flaming Torch by Owen Conquest · (ss)
- The Sign of the Flaming Torch by Charles Hamilton · (ss)
- The Sign of the Flaming Torch by Nipper · (na)
- The Sign of the Flying X by George Bruce Marquis · (na)
**The Sign of the Four**by Arthur Conan Doyle · (Spencer Blackett, October 1890, n.)- The Sign of the Fourth by Ken Janssens · (ss)
- The Sign of the Goat by Jan J. B. Kuipers · (ss)
- The Sign of the Goat by Thomas McMorrow · (ss)
- Sign of the Golden Gun by Byron W. Dalrymple · (ss)
- The Sign of the Golden Swan by C. Malcolm Hincks · (ss)
- The Sign of the Golden Swan by John Ernest McCann · (ss)
- Sign of the Gong by Earl W. Scott · (ss)
- The Sign of the Goose by G. C. Edmondson · (ss)
- The Sign of the Grinning Skull by [uncredited] · (n.)
- Sign of the Gross by S. H. Ross · (ss)
- Sign of the Gun-Wolf by William Corcoran · (ss)
- “Sign of the Hawk” by Ronald Fleming · (n.)
- “Sign of the Hawk” by Renee Frazer · (n.)
- The Sign of the Jockey by John Robert Stuart Pringle · (sl)
- The Sign of the Jockey by Gerald Verner · (sl)
- Sign of the Jumna by Homer Bezaleel Hulbert · (ss)
- The Sign of the Key and the Cross by Henri de Régnier · (ss)
- The Sign of the Key and the Cross by Sophie Earl · (ss)
- Sign of the Killer by Charles A. Freeman · (ts)
- Sign of the Killer by Harold R. Stoakes · (ss)
- The Sign of the King by Mary Soon Lee · (pm)
- The Sign of the Kurri Hustag by Chris Sewell · (ss)
- The Sign of the Last Button by Michael White · (ss)
- The Sign of “The Limping Hare” by E. M. Jameson · (ss)
- The Sign of the Lion by Thomas McMorrow · (??)
- The Sign of the Lizard by Philip Verrill Mighels · (sl)
- The Sign of the Lobstick by Douglas L. Durkin · (ss)
- The Sign of the Magna Mater by Fred Blosser · (ss)
- The Sign of the Maple Leaf by [uncredited] · (ms)
- The Sign of the Moon by H. M. Sutherland · (ss)
- The Sign of the Moonbow by L. Sprague de Camp · (br)
- The Sign of the Moonbow by David Johns · (br)
- Sign of the Noose by Robert Wallace · (na)
- The Sign of the Northmen by Henry Leverage · (sl)
- Sign of the Nutcracker by Mojave Lloyd · (ss)
- The Sign of the Oolah by Charles Tenney Jackson · (ss)
- Sign of the Owlhoot by Edwin K. Sloat · (nv)
- The Sign of the Painted Skull by Jay J. Kalez · (nv)
- The Sign of the Parrot by Pete Boggs · (ms)
- The Sign of the Prophet Jonah by Eliot McCormick · (ss)
- The Sign of the Puma by George L. Eaton · (n.)
- The Sign of the Puma by Harold P. Montanye · (n.)
- The Sign of the Purple Circle by Nipper · (na)
- Sign of the Ram by Lawrence G. Blochman · (nv)
- The Sign of the Ram by R. Austin Freeman · (ss)
- The Sign of the Ram by Thomas McMorrow · (??)
- The Sign of the Rat by Carroll John Daly · (nv)
- Sign of the Rebel Brigade by Joseph L. Chadwick · (nv)
- The Sign of the Red Arab by Edmund Snell · (na)
- The Sign of the Red Cross by Hamilton Wright Mabie · (ar)
- The Sign of the Red Cross by Nancy Vincent McClelland · (ar)
- Sign of the Red Geranium by Frederick Orin Bartlett · (sl)
- Sign of the Red Geranium by William Carleton · (sl)
- Sign of the Red Horseshoe by W. Ryerson Johnson · (nv)
- The Sign of the Sacred Scarab by Nipper · (na)
- Sign of the Salamander by Joshua M. Reynolds · (ss)
- Sign of the Salamander by Karl Edward Wagner · (na)
- The Sign of the Satyr by Leonard Noel Barker · (ss)
- The Sign of the Satyr by L. Noel · (ss)
- Sign of the Sawbones by Tom Parsons · (ss)
- The Sign of the Scaffold by Thomas B. Costain · (nf)
- The Sign of the Scales by Thomas McMorrow · (ss)
- The Sign of the Scar by George A. McDonald · (na)
- The Sign of the Scar by Robert Wallace · (na)
- The Sign of the Scarlet Cross by Eando Binder · (ss)
- The Sign of the Scarlet Cross by Claud Heathcote · (sl)
- The Sign of the Scissors by Lloyd Williams · (ss)
- The Sign of the Scorpion by Ella Sterling Cummins · (ss)
- The Sign of the Scorpion by Thomas McMorrow · (ss)
- The Sign of the Scorpion by Ella Sterling Mighels · (ss)
- Sign of the Scorpion by Valentine Wood · (nv)
- The Sign of the Serpent by John G. Brandon · (na)
- Sign of the Serpent by Hugh B. Cave · (na)
- The Sign of the Serpent by John Goodwin · (sl)
- The Sign of the Serpent by Sidney Gowing · (sl)
- The Sign of the Serpent by William Murray Graydon · (n.)
- The Sign of the Serpent by Reginald Jennings · (ss)
- Sign of the Serpent by Charles Rodda · (nv)
- The Sign of the Serpent by [uncredited] · (n.)
- The Sign of the Seven Sharks by Fulton Oursler · (nv)
- The Sign of the Seven Sins by William Le Queux · (na)
- The Sign of the Seven Skulls by A. L. Smith · (ss)
- The Sign of the Shadow by Alexander Teixeira de Mattos · (nv)
- The Sign of the Shadow by Maurice Leblanc · (nv)
- The Sign of the Shark by Albert Richard Wetjen · (ss)
- The Sign of the Sickle by Robert E. Howard · (pm)
- The Sign of the Sickle by Harry Klingsberg · (ss)
- Sign of the Sidewinder by Norbert Davis · (nv)
- The Sign of the Silhouette by Pierre Quiroule · (na)
- The Sign of the Silhouette by W. W. Sayer · (na)
- The Sign of the Silver Horseshoe by John Robert Stuart Pringle · (sl)
- The Sign of the Silver Horseshoe by Gerald Verner · (sl)
- The Sign of the Silver Kid by T. W. Ford · (nv)
- Sign of the Sixgun by Lee E. Wells · (na)
- The Sign of the Skull by Elliot W. Chess · (nv)
- The Sign of the Skull by J. Allan Dunn · (na)
- Sign of the Skull by James A. Goldthwaite · (ss)
- Sign of the Skull by Francis James · (ss)
- The Sign of the Skull by Charles H. Mansfield · (ss)
- The Sign of the Skull by W. E. Mansfield · (ss)
- The Sign of the Skull by Huan Mee · (ss)
- Sign of the Skull by Crawford Sullivan · (ss)
- The Sign of the Slack Hand by Wallace Irwin · (pm)
- The Sign of the Snake by Robert E. Howard · (ss)
- Sign of the Snake by Marte Richards · (ss)
- The Sign of the Snake! by E. Newton Bungey · (ss)
- The Sign of the Snake! by John Lance · (ss)
- The Sign of the Song by Robert Leslie Bellem · (ss)
- The Sign of the Spandau by Jefferson A. Dewar · (ss)
- The Sign of the Spear by Mitchell Mannering · (ar)
- The Sign of the Spider by Bertram Mitford · (ex)
- A Sign of the Spring by Warwick James Price · (pm)
- Sign of the Straddle Bug by Hascal Giles · (na)
- Sign of the Sun by Erle Stanley Gardner · (ss)
- Sign of the Sunflower by Luther A. Wert · (nv)
- The Sign of the Swami by Carolyn Gordon · (ss)
- The Sign of the Sword by Sylvia Allen · (ss)
- The Sign of the Sword by [uncredited] · (ms)
- Sign of the Talking Furs by Eric Allen · (ss)
- The Sign of the Tee Pee: The Story of Thorpe & Porter by Steve Chibnall · (ar)
- The Sign of the Three by Larry Lefkowitz · (ss)
- Sign of the Thumb by Paul L. Anderson · (ss)