You have to check if a Custom Item,which you want to add into your Server has all the files,which means the drop sprite,which is actually the item bmp,which is shown if you open your item inventory,just compressed as a sprite,then the male and female .spr and .act ,which is the most important thing for a Custom Item Sprite,because theese are the images,which are shown if the Player is wearing the Custom Item,like Wings,and then you need a collection bmp,which is shown if you right click the custom item. So Good Luck if you already found out how to edit a Custom Item.
Also,the visionary_tab was used with xRay,but xRay is no longer in use,because the xRay clients got outdated and now everyone uses the .lua and .lub files clients,because they're not outdated.