Work items are launched using the <ManualAction> directive. The form associated with a specified workflow can set the base context to variables.user. This eliminates the need to put user.variables in the variable name.
The WorkItem is the name space, so typical attribute names of the form:
complete (WorkItem attribute)
variables.* (task variables)
variables.<view>.accounts[*].*
variables.<view>.waveset.*
variables.<view>.accountInfo.*
:display.session (session for Owner)
Applies to both custom tasks and administrator approvals.