I think it's just a typo, but the docs I have for Interplay MAM v5 ("Interplay | MAM Data Model Format Reference", p. 26) says that for ModelAttributes,

If TYPE is float, TYPE_DIGITSRIGHT contains maximum number of digits right of the decimal point.

ConfDMLib: DMAttribute.type.floatDigitsRight

In looking at the XML I get from the web service, it looks like that should be TYPE_DIGITSAFTER. Is that just a doc error or is something changing between versions?

You are right it is a typo in the documentation.

The XML Element name must be TYPE_DIGITSAFTER nevertheless the property name in ConfDMLib is correct.

Actually it should read: 

If TYPE is float, TYPE_DIGITSAFTER contains maximum number of digits right of the decimal point.

ConfDMLib: DMAttribute.type.floatDigitsRight

Thank you for informing us we will update the Data model reference accordingly for the next release of Interplay | MAM.