Types of user exits

FND SRWINIT sets your profile option values and allows 
Oracle AOL user exits to detect that they have been called 
by a Oracle Reports program.[Before Report trigger, 
P_CONC_REQUEST_ID lexical parameter]

FND SRWEXIT ensures that all the memory allocated for 
Oracle AOL user exits has been freed up properly. [After 
Report trigger]

 

FND FORMAT_CURRENCY is used for MULTIPLE CURRNECY REPORTING 
(MRC)  [formula Column, P_MIN_PRECISION lexical parameter]

 

FND FLEXSQL this API is used for get 
ELECT/WHERE/HAVING/ORDER BY/GROUP BY from flex field 

tables.

 

FND FLEXIDVAL this API is used for get descriptions from 
flexfields, gets input from FND FLEXSQL.

Call this user exit to populate fields for display. You 
pass the key flexfields data retrieved by the query into 
this exit from the formula column. With this exit you 
display values,descriptions and prompts by passing 
appropriate token (VALUE/DESCRIPTION/APROMPT/LPROMPT).

it will take inputs from columns of query , the columns are 
defined  by FND FLEXSQL.