Refinement

• Refines the results of a query, by restricting the hit list or by modifying the document scores.

  occurs

  Indicates whether the refinement Must, MustNot, or Should occur in each hit. An additional option is Filter, which should be used for refinements that may match many documents, and should not influence the scoring. The most common examples of a Filter refinement are restricting the hit list to documents that contain a specified tag, and selecting a date range.

boost
For occurs other than Filter, this value defines how much influence the refinement should have on the scoring.
clause
An expression written in Lucene query syntax. The document fields are:

• ID : the document DocId.

• AUTHORITY : document authority.

• TOPICS : the recognized topics in the document. Each field value consists of the topicType and id joined by a / (forward slash) character. The colon character is not used as a separator because the colon is interpreted by Lucene as the separator between field name and field value. An example clause is TOPICS:concept/25648 (Zocor).

• TEXT : the analyzed (stemmed) text of the document.
• DOC_YEAR : the document modified date to resolution of one year.
• DOC_MONTH : the document modified date to resolution of one month.
• DOC_DATE : the document modified date to resolution of one day.

  For date formatting, see the Lucene DateTools documentation. Field values must be properly escaped and quoted.