For a character mode host, when true, any generated code will use the defined field length to pad the data entered with blanks.
Block mode hosts do not need this option, as in a block mode environment, the low-level Flynet entry functions for field formatted screens will automatically clear to the end of the field. Character mode hosts are keyed rather than "poked" so this kind of option is needed to optimize performance.
Use the true setting for a screen field that will be over-typing existing data and thus needs to accommodate a pre-existing value with a longer length than the new value being keyed.
