This range is splitted into groups for easier handle.
-10000 - -10099 Environment, Tracing, Filehandling, Misc
-10100 - -10199 Connection
-10200 - -10299 API handling
-10300 - -10399 Parameter, Column handling
-10400 - -10499 Data Conversion
-10500 - -10599 Retrieving results and array commands
-10600 - -10699 Statement execution
-10700 - -10799 Mapped Precompiler and Precompiler Runtime errors
-10800 - -10899 as above
-10900 - -10999 Fatal Errors
Details are available here