So your company has decided to submit SDTM datasets to FDA. You have worked tediously to make sure that your datasets comply with SDTM Implementation Guide (SDTMIG). You even validated your datasets with WebSDM. Can you be sure that your data will successfully load into FDA's Janus data warehouse? The short answer is No, as has been demonstrated by the Sanofi-Aventis team in their paper Experiences Submitting CDISC SDTM and Janus Compliant Datasets. The main issue is the inconsistency between how SDTMIG, WebSDM, and Janus classify the severity of violations for different validation requirements. Where SDTMIG might consider a requirement as variable and non-critical, Janus might consider it a high severity violation that will prevent a study from loading. The goal of OpenCDISC Validator project is to help the CDISC community ensure compliance with the standards across the entire clinical data life cycle, which includes the Janus data warehouse. As part of this effort we will work with the community to resolve inconsistencies between the specifications and to maintain the validation rules necessary to ensure Janus compliance. To illustrate the inconsistencies, we have published a listing of SDTM Validation Rules as defined in the draft Janus SDTM Validation Specification v.1 and cross-referenced them with the latest WebSDM v2.6 validation checks. The listing also tracks the rules that are currently supported by the OpenCDISC Validator. If you have experience creating Janus compliant datasets, please help us refine and improve the listing by providing feedback on our forum.