There are several different types of bands used on different bird species. Bands can be metal or plastic, and the unique identification number of each band may be etched or engraved onto the band. Some bands are brightly colored so they can be read at a distance without disturbing the birds, and more detailed bands may have informational codes that identify where and when the bird was first banded. Some countries and banding organizations use bands that have the address of the relevant conservation organization right on the band.