The X.500 standard defines the operations provided by the directory in a document called the Abstract Service Definition. DCE implements this standard with XDS API functions calls. The XDS API functions allow an application program to interact with the directory service. The standard divides these interactions into three general categories: read, search, and modify.
The XDS API functions correspond to the Abstract Service functions defined in the X.500 standard, as shown in the table below.
Mapping of XDS API Functions to the Abstract Services
| XDS Function Call | Abstract Service Equivalent |
| ds_read( ) | Read |
| ds_compare( ) | Compare |
| ds_list( ) | List |
| ds_search( ) | Search |
| ds_add_entry( ) | AddEntry |
| ds_remove_entry( ) | RemoveEntry |
| ds_modify_entry( ) | ModifyEntry |
| ds_modify_rdn( ) | ModifyRDN |