Generating SQL statements and corresponding commands, C1DataObjects uses this format string to create names to assign to command parameter Name property (IDbDataParameter.Name). For example, for a SQL Server database, the string can be "@{1}" or "@Par{0}". The latter ignores the suggested name and uses the (unique) parameter number to generate the parameter Name property value. For an Oracle database, examples of a correct format string are "{1}" or "Par{0}".

Reference

CustomProviderInfo Class
CustomProviderInfo Members
SqlParameterNameFormat Property