Envelope and message headers
UNA can define separators, UNB identifies the interchange, and UNH starts an individual message. These headers provide syntax, sender, receiver, timestamps, references, and the message type and version.
Segments and qualifiers
A segment name alone rarely tells the full story. Qualifiers determine whether a party is a sender or receiver, what a date represents, and which measurement or quantity is being reported.
Dates, intervals, and quantities
Energy time series must be interpreted with their period boundaries, resolution, unit, direction, and status. Viewing those fields together helps reveal gaps, duplicates, and unexpected values.