MRV files can be validated by using the XSD schema containing the description of the MRV format.
Schema versions can be found here.
Starting from version 6.1, MRV files begin with a reference to the schema to which the file is conformed:
<?xml version="1.0" encoding="UTF-8"?> <cml xmlns="http://www.chemaxon.com" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.chemaxon.com/marvin/help/formats/schema/mrvSchema_6_1_0.xsd" version="ChemAxon file format v6.1, generated by v6.1.0">
In previous versions, MRV format didn't have a reference to a schema:
<cml version="ChemAxon file format v6.0, generated by v6.0.0">
For these files, the recommended schema to use for validation is that of version 6.0.0.