Introduces a type group. You can only maintain a type
group via the ABAP/4 Dictionary (using Transaction SE11 ).
The name typepool must match the name in the ABAP/4
Dictionary . You can only define types and constants in type groups.
The names of all these types and constants must begin with the name of
the type group and an underscore.
Example
TYPE-POOL ABCDE.
TYPES: ABCDE_PACKED TYPE P,
ABCDE_INT TYPE I.