Ordering of controls

[David Chadwick <d.w.chadwick@salford.ac.uk>]

Dear All

During a discussion with Kurt about the ordering of LDAPv3 controls, it
became clear that different controls are used at different stages during
the processing of an LDAP operation. X.518 has the concept of a Name
resolution phase followed by an operation evaluation phase followed by a
results merging phase. These concepts are useful. For example

ManageDSAIT applies in the name resolution phase, to stop a referral
being acted upon.
The subentries control applies in the operation evaluation phase
The duplicateEntries and valuesReturnFilter controls are part of the
results merging phase.

The suggestion to the group is that we add these concepts to the LDAPv3
documentation and then request that in subsequent revisions of LDAP
extension IDs and RFCs the authors state which phase of the operation
their control applies to. This would help authors and implementors to
determine which controls to apply in which order.

regards

David