I write a lot of reports, and I can never remember whether to use

   <<foo|branches>>

or

   <<foo|branchcode>>

for instance. These *are* documented in the help page, but it would be helpful if they were in a tabular form, e.g.

+-----------------+--------------------------------------------------+-----------------------------+
| parameter       | what user sees                                   | what gets inserted in query |
+-----------------+--------------------------------------------------+-----------------------------+
| date            | date picker                                      | validly formatted date      |
| branches        | drop down of branch names                        | branch code                 |            
| itemtypes       | drop down of item type names                     | item type                   |
| categorycode    | drop down of patron category descriptions        | borrower ctegory code       | 
| (anything else) | drop down of auth-value descriptions in category | authorized value            |
+-----------------+--------------------------------------------------+-----------------------------+

This would be easier to find on the help page.