That's a new item's type in Alpha 3.5x. You may need to do something to gain one and by using it, learn a new crafting recipe.
“The Safety Box Book can be obtained by donating 30 items to the Museum and then collecting it as...Safety Box Book
“Learn to craft an Umbrella with Spine, Copper Bars, and Fiber Cloth. Can be received as a reward...Umbrella (Book)
“Learn to craft the Blade of Malice with the Enhanced Bronze Sword, Venom, and Mucus. It can be...Blade of Malice (Book)
“Learn to craft the Yellow Sapphire Necklace with the Topaz and Wild Cocoon. It can be obtained...Yellow Sapphire Necklace (Book)