This Technical Specification defines the application of medical waveform format encoding rules (MFER) to describe long-term electrocardiogram waveforms measured in physiological laboratories and health care clinics. It covers electrocardiograms such as bipolar 2, 3-lead, 12-lead that are measured by medical equipment such as Holter electrocardiograph and patient physiological monitors that are compatible with the medical waveform format Encoding rules (MFER) Technical Specification (ISO 22077‑1).