DBA_TABLESPACES - MIN_EXTLEN

Hi Gurus,

Can anyone tell me the significance of Min_Extlen field in DBA_TABLESPACES.

SQL> ;
  1 SELECT tablespace_name, initial_extent, next_extent,   2 max_extents, pct_increase, min_extlen   3* FROM dba_tablespaces
ORACLE - SQL> / TABLESPACE_NAME INITIAL_EXTENT NEXT_EXTENT MAX_EXTENTS PCT_INCREASE

MIN_EXTLEN                                       
------------------------------       --------------           -----------
----------             ------------               ----------

SYSTEM                       10240                 10240              121
50                        0                                       
USER_DATA                 10240                 10240              121
50                        0                                       
ROLLBACK_DATA         10240                 10240              121
50                        0                                       
TEMPORARY_DATA      10240                 10240              121
50                        0                                       
TS_DATA                       10240                10240              121
50                        0                                       
TS_INDEX                      10240                10240              121
50                        0                                       
TS_TMP                         10240                10240             121
50                        0                                       
TS_RBS                         10240                10240             121
50                        0