The document presents insights from the transition of the Polish national implementation guide for HL7 CDA standard into DECOR format, highlighting the eHealth program's goals in Poland and the adoption of HL7 CDA. Key observations include challenges with business rules, the use of abstract templates, and integration of open and closed templates in DECOR projects. Overall, the effectiveness of DECOR as a format for national HL7 CDA implementation is affirmed, aided by expert guidance.