I've never seen this term, and I'm wondering what it means, with regard to
NOTE: Input linework must be correctly noded for this function to work properly
this page helpfully shows some of the edge cases where this function would fail and return NULL. To summarise some examples...
or any case where the set/array of geometries doesn't form one or more polygons. Also, rounding/precision errors might come into play, and it may be that linestrings need to align in a consistent direction.
there may be other definitions of 'incorrectly noded' :)