Episode numbering needs a system as well as a value. A guide can carry an on-screen number, a structured sequence or an external identifier. Treating all those values as the same familiar S01E01 notation can produce apparent off-by-one errors or merge unrelated instalments.
XMLTV provides an episode-num field with a system attribute. The system tells the reader how to interpret the content. Keep that context with the value when inspecting, exporting or reporting a numbering problem.
Distinguish representation from identity
The XMLTV namespace scheme uses zero-based components, while an on-screen representation can reproduce the programme maker’s own label. The first season can therefore have an internal component beginning at zero without meaning “season zero” in the viewer’s usual sense.
Do not correct a structured value by adding one manually unless you are deliberately converting it through a documented rule. The application may already perform the presentation conversion. Editing the source and relying on that conversion can apply the adjustment twice.
Compare one known instalment
Multipart programmes and specials can require additional context. A part number is not automatically another full episode, and a special may not follow ordinary season ordering. Preserve what is known rather than inventing a complete sequence from partial data.
- Identify the programme and a specific episode using reliable title information.
- Record the raw episode value together with its stated system.
- Check the format’s interpretation of that system.
- Compare what the player displays, rather than only the source text.
- Report a conversion or source error with both representations clearly labelled.
Keep numbering separate from availability
A correct episode label does not prove that the corresponding item is playable or that all episodes are present. Likewise, a missing number can be a metadata omission even when the programme opens correctly. Record the observation at the layer where it occurs.
When moving a library, check whether the destination recognizes the original numbering system or imports only a display string. A successful title import can still lose structured season and episode relationships. That can affect sorting even though the programmes remain in the catalogue.
For support, include the show identity, the numbering system, raw value and displayed result. A harmless fictional example is enough to discuss the conversion rule. The desired result is consistent interpretation with the original identity preserved, not forcing every source into one assumed numbering style. Avoid mass renumbering until the format and destination behaviour are understood.
Useful answers
Does a zero in a structured episode value always mean a viewer-facing season zero?
No. Some schemes use zero-based components.
Should episode values be reported without their system?
No. The system is needed to interpret the value correctly.
Does correct numbering prove all episodes are available?
No. Metadata identity and catalogue availability are separate checks.