[Koha-devel] Why is Dewey in the su index?

[Magnus Enger]

Hi, all!

I just had a library ask me about how they could best search for a
specific Dewey number (and not as part of a call number, but on it's
own). After a bit of head-scratching I discovered that searching for
the Dewey-number as a subject gave good results (e.g.
/cgi-bin/koha/catalogue/search.pl?idx=su&q=355&op=and&idx=kw&op=and&idx=kw&sort_by=relevance).
Now the trouble is I was unable to leave well enough alone, and
started trying to figure out why Dewey is included in the su index.
And I'm still scratching my head...

Normally I would expect to find the answer in one of the following
files, but this seems like a dead end:

etc/zebradb/marc_defs/normarc/biblios/record.abs
melm 082        Dewey-classification:w,Dewey-classification:s

etc/zebradb/biblios/etc/bib1.att
att 13    Dewey-classification

etc/zebradb/ccl.properties
#Classification-Dewey   13  A classification number from    082
#                           the Dewey Decimal
#                           Classification, developed by
#                           Melvyl Dewey.
#Dewey-classification 1=13


I have tried also tried grep'ing throught the source for
Dewey-classification, with meager results (the mention in Search.pm is
just in a list of "available indexes"):

C4/Search.pm:                    'Dewey-classification',
etc/zebradb/biblios/etc/bib1.att:att 13    Dewey-classification
etc/zebradb/ccl.properties:#Dewey-classification 1=13
etc/zebradb/marc_defs/unimarc/biblios/record.abs:melm
676$a		Dewey-classification:w,Dewey-classification:s
etc/zebradb/marc_defs/normarc/biblios/record.abs:melm 082
Dewey-classification:w,Dewey-classification:s
etc/zebradb/marc_defs/marc21/biblios/record.abs:melm 082
Dewey-classification:w,Dewey-classification:s
koha-tmpl/opac-tmpl/prog/en/modules/opac-browser.tt:
 <a href="opac-search.pl?q=Dewey-classification:[%
LEVEL_LOO.classification |uri %]">[% LEVEL_LOO.description |html
%]</a>
koha-tmpl/opac-tmpl/prog/nb-NO/modules/opac-browser.tt: <a
href="opac-search.pl?q=Dewey-classification:[%
LEVEL_LOO.classification |uri %]">[% LEVEL_LOO.description |html
%]</a>

If anyone could shed some light on why Dewey-numbers are available in
the su index I would be eternally grateful!

Best regards,
Magnus Enger
libriotech.no