Field help (ADSCLBLNG) 

This field determines the maximum size by default in the clob fields (character large objects) stored in the database. These fields corresponds notably to the texts stored in the database.

This field is defined to the power 2 : 1 equivalent to 2 Kb, 2 to 4 Kb, 3 to 8 Kb etc (the corresponding value is displayed, it can go up to 20, which corresponds to 1 Gb).

It should be noted that each field of the type clob can be sized differently in the database (if the data type carries the length explicitly, this default length is not used).