How are block key values assigned?

Any of the following definitions can be used as the value of the block key item:

By default, the RefName of the study event.
If the RefName of the study event contains a double underscore (for example, Week2__21), the value that follows the double underscore.
The Block Key Value custom property for the study event. If a value is specified for the Block Key Value custom property, that value overrides the block key value formed from all or a part of the RefName.

For common visits, the value of the Shared Form Block Key custom property on the study design becomes the value of the block key in data mappings for the internal visit definition (the CommonCRF visit) that the InForm application requires for common forms.

The resulting block key value must conform to the specifications of the data series for the block key item in the context panel:

The data type must convert to a compatible data type.
The length must be within the length specified in the DB Format Length CIS custom property.
If the data type of the data series is float, the precision must be within the precision specified in the DB Format Float Precision CIS custom property.

For example, validation fails if:

The block key value is First but the block key item has a type of Integer.
The block key value is 99 but the page key item has a Length of 1.