RuleCheck is a web-based decision supporting tool originally designed for the competent PSC authorities in the Paris MoU domain. RuleCheck being an up to date Repository of Maritime Legislation provides to users.

IMO Conventions, Codes, Resolutions and Circulars, ILO Conventions and Guidelines, Maritime related EU Regulations and Directives and the Paris MoU Manual and Instructions. RuleCheck facilitates the work of the PSCOs by filtering the applicable requirements of the international instruments and regional procedures for a specific ship according to its type, construction date, size, etc. or through the correlation of an identified deficiency code with applicable reference from an international convention. The search function gives PSCOs ready access to relevant and targeted information, avoiding the need to consult hard copies.

Since 2015 the tool has been enhanced and it is also accessible to inspectors from the PSC MedMoU (under the SAFEMED project), the PSC Black Sea MoU (under the ex TRACECA project), the Caribbean MoU, the Indian Ocean MoU, the Tokyo MoU, the Riyadh MoU under respective cooperation agreements, to Accident investigation authorities in the EU Member States and a limited number of maritime Administrations in their capacity as Flag States.