Explained below is the basics of Value Set.

What is a value set and where is it used?
Value set is primarily the List of Values(LOV) to restrict and mantain consistencies in entering or selecting the values. It is also the place holders to allow user enter a value. Oracle Application Object Library uses value sets as important components of key flexfields, descriptive flexfields, and Concurrent Request Submission.

What are the Format Types the value set have?
* Character
* Number
* Time
* Standard Date, Standard Date Time
* Date, Date Time
Note that Date and Date Time value set formats are obsolete and are provided for backward compatibility only. For new value sets, use the the format types Standard Date and Standard Date Time.

What are the validation types?

None:

* There is no validation done for this type of value set, hence allows user to enter any value.

Independent:

* It provides a list of pre-defined values. The predefined values are entered seperately.

Dependent:

* Same like Independent Value Set, except the List of Values shown to you will depends on which the Independent value you have selected in the Prior Segment.
* Must define your independent value set before you define the dependent value set that depends on it.
* Must create at least one dependent value for each independent value.

Table:

* The list of value is created based on database tables
* Allows to write simple queries, joins, order by etc
* The value, meaning and ID can be used to display a value, description to the value but return ID to the calling program or screen.
* Additional columns can also be displayed. The syntax is column "column title(size)",.... e.g. order_type "SO Order Type(40)"
* Can also create dependent values to filter LOV data based on parameter value selected earlier. This can be done using :$FLEX:.value_set_name in the where clause.

Special & Pair:

Pair validation value set allows to select a range of concatenated Flex field segments as parameters to the report. The special value set is used to perform special validation. This is used to enter the entire key flexfield segment in the single parameter of the report/calling entity.

Translatable Independent & Translatable Dependent:

* This is similar to Independent and Dependent value set except that translated values can be displayed to the user.

APIs to create value set
The FND_FLEX_VAL_API package can be used to create different types of value sets.
* VALUESET_EXISTS - To check if value set exists
* DELETE_VALUESET - To delete value set. The value set can only be deleted if it is not being referenced by any program or entity.
* CREATE_VALUESET_NONE
* CREATE_VALUESET_INDEPENDENT
* CREATE_VALUESET_DEPENDENT
* CREATE_VALUESET_TABLE
* CREATE_VALUESET_SPECIAL
* CREATE_VALUESET_PAIR

What are the oracle tables that store value set information?
* FND_FLEX_VALUE_SETS
* FND_ID_FLEX_SEGMENTS
* FND_FLEX_VALUE
* FND_FLEX_VALIDATION_EVENTS
* FND_FLEX_VALUE_RULE_LINES
* FND_FLEX_VALUE_RULE
* FND_FLEX_VALUE_RULE_USAGE
* FND_FLEX_VALIDATION_TABLES