The recent Ecosystem Accounting standards of the System of Economic Environmental Accounts (SEEA EA) constitute a major step towards standardising and operationalising the concept of ecosystem condition. Similar concepts can be discovered in several EU-level and national policy frameworks, which predate SEEA EA. Nevertheless, these frameworks apply highly different terminologies which conceals both similarities and differences, hindering mutual learning and collaboration. In this report we compare major European biodiversity policies (e.g. Water Framework Directive, Marine Strategy Framework Directive) and national frameworks (e.g. the Index-Based Ecological Condition Assessment framework in Norway) that apply dimensionless condition indicators measured on a harmonised 0-1 scale to characterise the condition of ecosystems. Similarly to SEEA EA, these frameworks use references (reference levels and reference conditions) for rescaling raw variables to the common dimensionless scale. These references have a central role in establishing the salience, credibility, and legitimacy of the rescaled values as meaningful metrics of ecosystem condition. Here we present the main commonalities in the EU approaches using a simple harmonised terminology building on SEEA EA, with a particular focus on the use of references in these frameworks. This report is a deliverable of the EU Horizon Research and Innovation Action, Science for Evidence-based and sustainabLe decIsions about NAtural capital (SELINA), which aims to provide robust information and guidance to support ecosystem restoration across the EU.