Export provides online help. Enter exp help=y on the command line to invoke it. 

Export: Release 8.1.6.0.0 - Production on Wed Oct 6 15:23:43 1999

(c) Copyright 1999 Oracle Corporation.  All rights reserved.

You can let Export prompt you for parameters by entering the EXP
command followed by your username/password:

     Example: EXP SCOTT/TIGER

Or, you can control how Export runs by entering the EXP command followed
by various arguments. To specify parameters, you use keywords:

     Format:  EXP KEYWORD=value or KEYWORD=(value1,value2,...,valueN)
     Example: EXP SCOTT/TIGER GRANTS=Y TABLES=(EMP,DEPT,MGR)
               or TABLES=(T1:P1,T1:P2), if T1 is partitioned table

USERID must be the first parameter on the command line.

Keyword  Description (Default)        Keyword      Description (Default)
--------------------------------------------------------------------------
USERID   username/password            <b>FULL         export entire file (N)</b>
BUFFER   size of data buffer          OWNER        list of owner usernames
FILE     output files (EXPDAT.DMP)    TABLES       list of table names
COMPRESS import into one extent (Y)   RECORDLENGTH length of IO record
GRANTS   export grants (Y)            INCTYPE      incremental export type
INDEXES  export indexes (Y)           RECORD       track incr. export (Y)
ROWS     export data rows (Y)         PARFILE      parameter filename
CONSTRAINTS export constraints (Y)    CONSISTENT   cross-table consistency
LOG      log file of screen output    STATISTICS   analyze objects (ESTIMATE)
DIRECT   direct path (N)              TRIGGERS     export triggers (Y)
FEEDBACK display progress every x rows (0)
FILESIZE maximum size of each dump file
QUERY    select clause used to export a subset of a table
VOLSIZE  number of bytes to write to each tape volume

<b>FULL
Default: N 

Indicates that the Export is a full database mode Export (that is, it exports the entire database). Specify FULL=Y to export in full database mode. You need the 
EXP_FULL_DATABASE role to export in this mode. 
</b>