Layers are very useful for organizing information. In Terrain, layers are encoded into the feature ID. For example a stream layer might consist of all features beginning with the name ST. In this case a layer would be defined as ST* where * can be any character (wildcard). The layer ST* would match ST1, ST1a,ST1023 etc.
The ? character can be used to match any single character. E.g. 123? would match 123x, 123v but not 123 or 123xx.
