Hi all, I am using the OCLC Classify API. As show in the sample response snippet below the two attributes "sfa" and "nsfa" could hold different values. According to "http://oclc.org/developer/documentation/classify/response-details": sfa - classification number from the subfield $a of 082/092 or 050/090, or 060/096 nsfa - normalized classification number from the subfield $a of 082/092 or 050/090, or 060/096 However,I would like to know how this normalization is done. Thanks, Arash <recommendations> <graph>http://chart.apis.google.com/chart?cht=p&chs=350x200&chd= t:100.0&chtt=All+Editions&chdl=Classified (100.00%)</graph> <fast> <graph>http://chart.apis.google.com/chart?cht=p&chs=475x175&chd= t:100.0,16.666668,16.666668,16.666668&chl=Functional programming (Computer science)|Lambda calculus|Modality (Logic)|Type theory|</graph> <headings> <heading heldby="6" ident="fst00936086">Functional programming (Computer science)</heading> <heading heldby="1" ident="fst00991011">Lambda calculus</heading> <heading heldby="1" ident="fst01024350">Modality (Logic)</heading> <heading heldby="1" ident="fst01159972">Type theory</heading> </headings> </fast> <ddc> <mostPopular holdings="6" nsfa="510.78" sfa="510.7808"/> <mostRecent holdings="6" sfa="510.7808"/> <graph>http://chart.apis.google.com/chart?cht=p&chs=350x200&chd= t:100.0&chtt=DDC&chdl=510.7808</graph> </ddc> </recommendations>