# Indexes

Index names are composed of the following parts:

[X][C/M/T]NNN[P/S]

X - letter X is used as a leading character of all base index names prior to Version 2.0.0. Now the first character of product owner flag value should be used instead of letter X. For client specific implementation index in Oracle, use CM.

C/M/T - The second character can be either C or M or T. C is used for control tables (Admin tables). M is for the master tables. T is reserved for the transaction tables.

NNN - A three-digit number that uniquely identifies the table on which the index is defined.

P/S/C - P indicates that this index is the primary key index. S is used for indexes other than primary keys. Use C to indicate a client specific implementation index in DB2 implementation.

Some examples are:

- XC001P0
- XT206S1
- XT206C2
- CM206S2

Warning: Do not use index names in the application as the names can change due to unforeseeable reasons.
Parent topic: Naming Standards