yehster/openemr — comment on commit bb11e43fd8c4a28b3b191612a3597d2a8fb945e8
File: sql/database.sql line 230
By sunsetsystems:

Columns should not default to NULL unless there is a reason (and supporting code) to distinguish between an empty value and a null value. Suggest using "NOT NULL DEFAULT ''" for almost all varchars.