When adding a new parameter in BI Publisher you will see the following fields:
Identifier – The key for the parameter. Determines whether a list supports the parameter.
Data Type – String should be the default type. When using a supported parameter, select String for the type. See Primitive Parameters for more on Date, Boolean, and Integer parameters.
Default Value – The value entered in this field will be the default for the parameter whenever the report runs. Users will be able to see this value in P6.
Parameter Type – Text, Menu, and Date are the common types. Unless otherwise specified, you should use Text as the default for the supported parameters. If you need to select multiple values, use Menu.
Display Label – The text that displays in P6 for the parameter. If you do not set a display label, the identifier displays instead.