Tile Texture Display
Once you have loaded a .lnd (map) or data set the black area immediately to the right of the player selection and enable buttons will fill up with available tile textures, structures and features. This is the tile texture display. Each tile texture, structure and feature is numbered. You can scroll down through the list using the slider bar and arrow buttons on the right edge. The currently selected tile texture, structure or feature is highlighted with a white rectangle. Clicking on another tile texture, structure or feature will select it. Double clicking on a tile texture will bring up the Paint Orientation dialog box (see "Rotation & Flips" for details).
This is a very old map editor. Use the new map editor instead: