I'm encountering an issue when I attempt to select custom data fields that have been added to an entity. If the custom field has an underscore in the field name, it seems to consider it an invalid filter name when I try to add a data filter to another DLAP command, such as GetCourse2 or ListEnrollments
"message":"Invalid data filter: (custom_field)",
If I use a custom field without an underscore (or using a dash) it works as expected.
This is not a showstopper issue, but it does conflict with the guide given in the Free Form XML documentation:
"As elements are matched by name, you should use a unique name for your element. We recommend using a unique customer prefix for the element name, such as customername_elementname."