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Records with empty or null values will appear at the top of the search results.
As per JIRA OLE_2194,
2nd indicator in MARC is non-filing character. need to use rules for these in applying sort/display standards. Ex. 245 1 3 $aAn April Shower- 2nd indicator is "3". Ignore first 3 characters, ie "An(space)" in applying sort rule
3.4 Solr-specific sorting features
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