Those who possess the Mark of Making can mend and create inanimate objects with its power.
House Cannith holds power over the Mark of Making and their Tinkers Guild is widely travelled and respected. The house also boasts a second guild, the Fabricators Guild, made up of members who possess lesser or greater dragonmarks and are able to not only mend broken items but create entirely new ones. Those who are not marked usually take on roles well off artisans or in rarer cases mundane tinkers.
In 3.5e, the Mark of Making was a chain of three feats for humans that gave innate spellcasting focused on spells that tied into creating and making, beginning with the Least Dragonmark feat, and reaching maximum power with the Greater Dragonmark feat. Obtaining the Siberys Dragonmark was only possible by possessing neither a dragonmark nor aberrant mark, being a human, and joining the Heir of Siberys prestige class. In 4th edition, the Mark of Making was a feat that gave access to rituals to infuse items.
In 5th edition the Mark of Making is a variant race option for Humans that replaces the human Ability Score Increases with Increases to Intelligence and Dexterity, bonuses to ability checks and innate spellcasting, and if the character has the Spellcasting or Pact Magic features, adds a set of spells as new choices they may select from to any and all spell lists that character may have access to through those features.