Bug 11460: Remove MARC21 default mapping from itemcallnumber system preference

The mapping in the itemcallnumber system preference is only valid
for MARC21 libraries using DDC classification, but not for libraries
using UNIMARC or other classification.

This patch suggests to remove the default mapping and start new installations
with an empty value.

To test:
- On an emtpy database
- Apply patch
- Run the web installer, selecting either MARC21 or UNIMARC
- Verify that the itemcallnumber system preference is empty
- Verify the description now also include examples for UNIMARC

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

installer/data/mysql/mandatory/sysprefs.sql

@@ -282,7 +282,7 @@ INSERT INTO systempreferences ( `variable`, `value`, `options`, `explanation`, `
 ('item-level_itypes','1','','If ON, enables Item-level Itemtype / Issuing Rules','YesNo'),
 ('itemBarcodeFallbackSearch','',NULL,'If set, uses scanned item barcodes as a catalogue search if not found as barcodes','YesNo'),
 ('itemBarcodeInputFilter','','whitespace|T-prefix|cuecat|libsuite8|EAN13','If set, allows specification of a item barcode input filter','Choice'),
-('itemcallnumber','082ab',NULL,'The MARC field/subfield that is used to calculate the itemcallnumber (Dewey would be 082ab or 092ab; LOC would be 050ab or 090ab) could be 852hi from an item record','free'),
+('itemcallnumber','',NULL,'The MARC field/subfield that is used to calculate the itemcallnumber (Dewey would be 082ab or 092ab; LOC would be 050ab or 090ab) could be 852hi from an item record','free'),
 ('ItemsDeniedRenewal','','','This syspref allows to define custom rules for denying renewal of specific items.','Textarea'),
 ('KohaAdminEmailAddress','root@localhost','','Define the email address where patron modification requests are sent','free'),
 ('KohaManualBaseURL','https://koha-community.org/manual/','','Where is the Koha manual/documentation located?','Free'),

koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/cataloguing.pref

@@ -74,7 +74,8 @@ Cataloging:
         -
             - Map the MARC subfields
             - pref: itemcallnumber
-            - "to an item's callnumber. List multiple comma-separated fields to check them sequentially. Each field can include multiple subfields. The order of the subfields in the record will be preserved. For example: '082ab,092ab' will look in the 082$a and 082$b, then the 092$a and 092$b. Examples (for MARC21 records): Dewey: 082ab,092ab; LOC: 050ab,090ab; from the item record: 952hi."
+            - "to an item's callnumber. List multiple comma-separated fields to check them sequentially. Each field can include multiple subfields. The order of the subfields in the record will be preserved. For example: '082ab,092ab' will look in the 082$a and 082$b, then the 092$a and 092$b."
+            - "Examples for MARC21: Dewey: 082ab,092ab; LOC: 050ab,090ab; from the Koha record: 942hi. Examples for UNIMARC: Dewey: 676a; LOC: 680ab."
         -
             - Display MARC subfield
             - pref: AlternateHoldingsField