MDAC 2.5 SDK - OLE DB Programmer's Reference
Chapter 25: MDX Grammar

Leveling Rules for MDX Set Value Expressions

1. Support for <desc_flags> other than SELF is optional. Consumers can check the value of MDPROP_MDX_DESCFLAGS to see which <desc_flags> the provider supports.
   
   
2. Consumers can check the value of the MDPROP_MDX_SET_FUNCTIONS property to see whether a provider supports set functions.

The ability to have expressions containing nonmeasure dimension members in the <numeric_value_expression> argument of set functions is optional. For example, if Revenue and Cost are measures and USA is a member of the Geography dimension, then in set functions that take a <numeric_value_expression> argument, the support for expressions such as Revenue/3 and (Revenue - Cost)/Cost*100 is mandatory. However, support for expressions such as (USA, Sales)/3 is optional. Consumers can check the value of the property MDPROP_MDX_NONMEASURE_EXPRESSIONS to see whether a provider supports this feature.