The odd "Q19700 pour Wikidata" is a strange ref="" key somebody attached to the OSM Relation id#11888769 for the River Taff. YAAC treats ref="" attributes of a tag as a highway route number (like the M5 symbol you can see near Gloucestershire). But this one is very poorly formatted, as the value provided could not be used automatically to look up other data about the geographical feature (due to the "pour Wikidata" suffix in the text).
