Cochrane Handbook
See Section 6.6

CRD’s Guidance for Undertaking Reviews in Health Care: Documenting the search process
"...provides practical guidance for undertaking evidence synthesis based on a thorough understanding of systematic review methodology."

PRISMA
"PRISMA stands for Preferred Reporting Items for Systematic Reviews and Meta-Analyses. It is an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses."

Standards for Reporting Systematic Reviews [Standard 5]
Finding What Works in Health Care: Standards for Systematic Reviews (from the Institute of Medicine March 2011) 

Equator Network [Enhancing the QUAlity and Transparency Of health Research]

-an international initiative that seeks to improve reliability and value of medical research literature by promoting transparent and accurate reporting of research studies