In version 1.01.13 the parameter aggregateType was change to an array. The corresponding text states:

The aggregateType[] parameter allows clients to request multiple Aggregate calculations per requested NodeId. If multiple Aggregates are requested, then a
corresponding number of entries are required in the NodesToRead array. For example to request Min and Max Aggregates for NodeId FIC101, would require NodeId FIC101 to appear twice in the NodesToRead array request parameter.

This is not clear to me. If you request Min and Max Aggregate and three nodes FIC101, FIC102 and FIC103. What is the size and ordering of the arrays:

(Option 1)
aggregateType[]
min
max
NodesToRead[]
FIC101
FIC101
FIC102
FIC102
FIC103
FIC103

(Option 2)
aggregateType[]
min
max
NodesToRead[]
FIC101
FIC102
FIC103
FIC101
FIC102
FIC103

(Option 3)
aggregateType[]
min
max
min
max
min
max
NodesToRead[]
FIC101
FIC101
FIC102
FIC102
FIC103
FIC103

The aggregateType[] parameter allows clients to request multiple
Aggregate calculations per requested NodeId. If multiple Aggregates are requested, then a corresponding number of entries are required in the NodesToRead array.
For example to request Min Aggregate for NodeID FIC101, FIC102 and both Min and Max Aggregates for NodeId FIC103 would require NodeId FIC103 to appear twice in the NodesToRead array request parameter.
aggregateType[] NodesToRead[]
min FIC101
min FIC102
min FIC103
max FIC103

Added clarifying text to section 5.3.4.2 Read processed functionality

If the Server the array of aggregates does not match the array of NodesToRead, the Server shall return a StatusCode of Bad_AggregateListMismatch

The aggregateConfiguration parameter allows clients to override the Aggregate configuration settings supplied by the AggregateConfiguration object on a per call basis. See [UA Part 13] for more information on Aggregate configurations. If the Server does not support the ability to override the Aggregate configuration settings it shall return a StatusCode of Bad_ArgumentInvalid.

OPC UA Part 11 - Historical Access DRAFT 1.01.14 Specification" - June 22, 2009

Discussed Telecon Aug 31st