Below are links to important resources for directors.
WBF 2017 Laws of Duplicate Bridge (PDF)
ABF/WBF System Cards (website)
ABF Alerting Regulations (PDF)
Alerting Rules Summary compiled by NSWBA (PDF)
Guide to Bridge Scoring compiled by NSWBA (PDF)
Preferred table movements compiled by NSWBA (PDF)
Bridge Victoria tournament regulations (PDF)
ABF Further Resources e.g. Scoresheets and Scoring Software (website)
These youtube videos by English Bridge Union may also be helpful to clarify common director calls.