9.4.3.3.3.6 gg.handler.name.format.nullColumnChar

Specifies a special column prefix for a column value that exists in the trail and is set to NULL.

The character used to represent the state of the column can be customized. For example:

gg.handler.handler1.format.nullColumnChar=N

By default, the null column value is set to an empty string and does not show.