| Cluster BTree Index | Longint | 3 | B-Tree type index using clusters. This type of index is optimized when the index contains few keywords, i.e. when the same values occur frequently in the data. | 
                | Default Index Type | Longint | 0 | 4D specifies the index type (excluding keywords indexes) that is the most optimized according to the contents of the field. | 
                | Keywords Index | Longint | -1 | Permits word-by-word indexing of field contents. This type of index can only be used with fields of the Text, Alpha or Picture type. Warning: Keywords indexes cannot be composite. | 
                | Standard BTree Index | Longint | 1 | Standard B-Tree type index. This multi-purpose index type is used in previous versions of 4D |