Php/docs/solrquery.setmlt
From Get docs
SolrQuery::setMlt
(PECL solr >= 0.9.2)
SolrQuery::setMlt — Enables or disables moreLikeThis
Parameters
flag
TRUE
enables it andFALSE
turns it off.
Return Values
Returns the current SolrQuery object, if the return value is used.