I am using IBO version 3.6Bc and have detected the following bug.

IBODatabase.ColumnAttributes are
CHRONIC_CONDITION_SUBTYPE=BOOLEAN=Y,N; <- This is Char(1) column name
TRUE_FALSE=BOOLEAN=T,F; <- This is Domain name Char(1)

IBODatabase.FieldEntryTypes := [fetDomainName]

With CHRONIC_CONDITION_SUBTYPE column = Y
IBOQuery.FieldByName('CHRONIC_CONDITION_SUBTYPE').AsString = ''
IBOQuery.FieldByName('CHRONIC_CONDITION_SUBTYPE').AsBoolean = False

IB_Query.FieldByName('CHRONIC_CONDITION_SUBTYPE').AsString = 'Y'
IB_Query.FieldByName('CHRONIC_CONDITION_SUBTYPE').AsBoolean = True

Clearly, both types of dataset should give the same results.

If IBODatabase.FieldEntryTypes := [] then fields not based on domain names
work as expected, but of course the domain based fields are no longer
recognized as Boolean.

So now I am in the awkward position of having completed the tedious task of
changing some 600 source files to use Boolean definitions....

Brian