SOLR-12581, Alexandre asked the tangential question below, which i've spun off into it's own jira...
Sort of a side-question, but this work [adding new options to the JSON faceting relatedness() aggregation] seems to overlap/compliment the significantTerms work done for streaming/QueryParser: http://lucene.apache.org/solr/guide/7_4/stream-source-reference.html#significantterms
Are we saying SignificantTerms is for simpler use cases (as fore/back queries are corpus-wide) and then go into relatedness() for more complex analysis?
Should the options be roughly compatible where it makes sense and/or similarly named?
Just wondering because I could see this confusing newbies trying to see when to use which option.