The present disclosure is concerned with a validation of a configuration description of automated devices in a power network such as a Substation Automation (SA) system, or of a part or component thereof such as an individual Intelligent Electronic Device (IED), that is extended beyond the mere XML schema validation as provided by the known SCL-validation tools. In particular, the disclosure introduces machine-based validation of notations, requirements and/or conventions to be respected by the configuration description and/or the SA system, but not incorporated in or represented by the standardized syntax of the XML schema as defined in part 6 of the IEC 61850 standard. To this end, notations, requirements and/or conventions are initially converted into, or defined as, extended or augmented rules encoded in computer readable format. The content or information of a file having an Substation Configuration description Language (SCL) compliant description of an SA system, or of a part or component there of, is then read by parsing the file and checked for conformance to the rules. Any inconsistency, error, wrong configuration or insufficient description found is displayed to a user, who may then correct the content or information in the file. The procedure according to the disclosure can contribute, in an automated manner, to the correctness of the description of a Substation Automation (SA) system beyond the pure syntactical adherence to the IEC 61850 standard.