B757-200
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 1
Situational Awareness; Training / Qualification; Communication Breakdown; Confusion; Distraction
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Company Policy; Human Factors; Procedure
I was on LC (Local Control) during the event in which the incident occurred.  I was briefed in mid-December that the B757 was to be treated as a large aircraft.  I cleared Aircraft X for takeoff on runway 15; I instructed Aircraft Y to LUAW (Line Up and Wait) on runway 8 after getting clarification from a supervisor that this was in fact okay to do now that the B757 was to be treated as a large. Shortly after Aircraft X rotated through the intersection I cleared Aircraft Y for takeoff on runway 8.  Inaccurate briefings for the RECAT change led to this misunderstanding of the rule and how to use it.  Also being told by management that this was okay also played a small role in the event.I think that if there is a briefing with something so critical they should put emphasis on what rules remain the same; and what rules are do not remain the same.  I also believe we should not be briefed on something that isn't officially implemented.  If it's something they are working on or trying to get clarification the brief should be held off.
BUR Local Controller reported of a loss of separation due to lack of understanding of wake turbulence rules.