this may help. i found this by searching yahoo and typed in (different type of water fowl bands) here is the web cite http://www.pwrc.usgs.gov/bbl/homepage/aboutaux.htm
Web Tags and Plasticine Bands
Web tags are small markers of metal with a code (usually one or more letters) identifying the bander on one side and a number indicating the individual bird. The tags were developed to mark fingerling fish and have been adopted by bird banders for use on waterfowl chicks. Web tags may identify the local area or nest site of the bird, or be part of a study on chick growth and survival. The use of web tags allows individual marking of birds that were too small to band. Because web tags are used on chicks, they are the only auxiliary marker that is allowed to be used without banding the bird with a federally numbered band without special permissions. If the bird is later trapped and is large enough for banding, the band is added to the bird at that time. Web tags can allow banders to be more precise in their age determinations that might be possible using the birds physical appearance alone, as the tag will indicate the exact year hatched.