I assume that you were talking about the 'Runtime Variables' section of the wiki:
https://wiki.koha-community.org/wiki/SQL_Reports_Library#Runtime_Variables
Yup.
... Nick, Jesse (pianohacker) and I have all played with this at one time or another, and I think that our consensus was that trying to set runtime variables is to avoid having to re-enter run-time parameters is a crapshoot -- it's possible to make it work sometimes, but it's hard to get right.
So I think that you'll have to re-enter parameters by hand until Koha 18.05, when we get this enhancement that makes the problem go away:
Bug 9634 : Allow for parameters re-use on SQL reports URL : https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=9634 Priority : P5 - low Assigned To : nick@bywatersolutions.com Urgency : enhancement Status : RESOLVED
OK, excellent. Thank you, Barton. Cheers, Cab Vinton