Unrecognized Tag
Q-1-22 — Unrecognized Tag
A YAML tag is not one of the tags Quarto knows how to interpret.
What this means
Quarto reserves a small family of YAML tags for controlling merge behavior and value interpretation. This error fires when a value carries a tag Quarto does not recognize as one of those — usually a custom tag from another tool or a tag that does not match the shape Quarto’s tag parser expects.
Recognized tags combine merge operations and interpretation hints:
!prefer, !concat, !md, !str, !path, !glob, !expr,
and underscore-joined combinations such as !prefer_md.
Why this happens
The two typical situations:
- A tag from a different tool has appeared in Quarto’s configuration. Custom tags from a data-processing pipeline, for instance, may carry through into a configuration file by accident.
- A tag that looks like a Quarto tag but is not. A misspelled
recognized tag — different from
Q-1-21, which warns about an unknown component inside an otherwise well-formed tag — may surface here when the parser cannot fit it into the expected shape at all.
How to fix
Remove the tag if the value does not need it. The value will be treated as an ordinary YAML scalar.
If you intended a Quarto tag, check that you used one of the recognized names listed above. Quarto’s tag parser is strict about the components it accepts.