Robert, thanks so much for replying with your findings! Super helpful.

Based on the record you shared, I noted a few differences between what I'm
seeing with Voilà and "real" WorldCat:

   - Voilà does not include OCLC numbers; the 001, 003, and 035 are
   stripped (likely other fields as well)
   - Voilà returns records encoded in MARC8 whereas WorldCat returns
   records encoded in UTF8

I tried more searches against Voilà's Z39.50 server. In every case where
there should be an accented character, the same corruption occurs.

I also noticed that WorldCat's Z39.50 server uses the hostname zcat.oclc.org
and is documented quite differently
<https://help.oclc.org/Metadata_Services/Z3950_Cataloging/Get_started/Configuration_guide_for_OCLC_Z39.50_Cataloging>
from FirstSearch's Z39.50 service, which uses the hostname fsz3950.oclc.org.
The documentation for FirstSearch Z39.50
<https://help.oclc.org/Discovery_and_Reference/FirstSearch/Z3950_access/Z3950_configuration_for_FirstSearch_databases>
doesn't even mention encodings, which seems like quite a red flag in 2022.

Based on the hostname, it seems Voilà's Z39.50 server uses FirstSearch
Z39.50, not WorldCat Z39.50, and is limited to records and holdings for
members of Canada's national union catalogue. Either way, any characters
outside of the ASCII range are corrupted, and LDR[09] has been reset to '
'.

   - If Voilà's Z39.50 server is a view of FirstSearch Z39.50, then OCLC
   added a layer to strip the OCLC fields which introduces corruption.
   - If it is a copy of a subset of WorldCat, then during the
   dump/transform/load process, OCLC strips the OCLC fields in a way that
   introduces corruption.

I suppose I should report this problem to Library & Archives Canada, as
they are OCLC's direct customer and hopefully have some clout. I do wonder,
though, if other national union catalogues that rely on OCLC are suffering
the same issues with their Z39.50 servers.

Best,
Dan.

On Wed, Nov 2, 2022 at 2:49 PM Haschart, Robert J (rh9ec) <
[log in to unmask]> wrote:

> Dan,
>
> I have seen something similar recently.   We (at the University of
> Virginia) were starting to see records containing the � character.​   I
> wrote a simple script to take a list of records containing that character,
> and extract the OCLC number, and then programatically perform a look-up for
> that OCLC number in WorldCAT via z39.50    The script would then compare
> our record with the one retrieved from OCLC and replace the fields
> containing the � character with the corresponding field from the record
> from OCLC.
>
> For the most part this was working, but in several cases the record
> retrieved from OCLC contained the � character.    It is not merely an
> encoding/translation error since multiple different characters have been
> replaced with that character.   Moreover, in some of the records returned
> there are some fields that contain correct accent marks while other fields
> that seemingly ought to contain the same accent mark, the accent mark has
> the � character substituted in instead.
>
> One example shown below is the record for OCLC number     682540414
> (ISBN   9782760521292)
>
> Additionally, I used both my marc4j- based z39.50  libraries and the local
> copy of yaz-client to retrieve the exact record you used as an example.
>  The binary form of the record was identical for both methods of retrieving
> the record.   And there were no instances of the � character in the display
> of the record.   (shown even further below)
>
>
> --Robert Haschart
> University of Virginia Library
>
>
> LEADER 03689cam a2200769Mi 4500
> 001 ocn682540414
> 003 OCoLC
> 005 20221102142039.0
> 008 101122s1996    quc     o     000 0 fre d
> 006 m     o  d
> 007 cr |n|---|||||
> 040   $aEBLCP$beng$epn$cEBLCP$dOCLCQ$dAUW$dOCLCO$dP@U
> $dOCLCF$dOCLCO$dOCLCQ$dCNKUC$dFVL$dOCLCQ$dOCLCA$dOCLCQ$dOCLCO$dOCLCQ$dJSTOR$dOCLCQ$dOCLCO$dQGK$dOCLCO$dOCL
> 066   $cZsym
> 016   $z96940719X
> 019   $a1259108319
> 020   $a9782760521292
> 020   $a276052129X
> 020   $a1441600825
> 020   $a9781441600820
> 035   $a(OCoLC)682540414$z(OCoLC)1259108319
> 037   $a22573/ctv18n0fbx$bJSTOR
> 050  4$aHD938
> 072  7$aBUS$x043000$2bisacsh
> 082 04$a338.4/791
> 100 1 $aLaplante, Marc.
> 245 12$aL'expérience touristique contemporaine :$bFondements sociaux et
> culturels.
> 260   $aQuébec :$bPresses de l''niversite du Quebec,$c1996.
> 300   $a1 online resource (204 pages)
> 336   $atext$btxt$2rdacontent
> 337   $acomputer$bc$2rdamedia
> 338   $aonline resource$bcr$2rdacarrier
> 490 1 $aCollection Tourisme
> 505 0 $aTable des matières; Liste des tableaux; Liste des figures;
> Introduction; Partie 1_L'enracinement du tourisme dans la socioté moderne;
> Chapitre 1_Touriste et tourisme d'hier et d'aujourd'hui; Chapitre
> 2_Sociétés et cultures de l'Occident industrialisé; Partie 2_Les
> dimensions de la culture touristique actuelle; Chapitre 3_L'expérience
> touristique comme expérience culturelle; Chapitre 4_La culture touristique
> personnelle; Chapitre 5_La culture touristique institutionnalisée;
> Conclusion; Guide bibliographique.
> 520   $aPour comprendre le tourisme comme fait social et culturel typique
> des sociétés postindustrielles, ce livre présente d'abord les principaux
> rapports entre tourisme et société puis élabore le concept de culture
> touristique.
> 588 0 $aPrint version record.
> 504   $aComprend des réf. bibliogr.
> 546   $aFrench.
> 650  0$aTourism and the arts.
> 650  0$aTourism$xSocial aspects.
> 650  0$aTourism.
> 650  0$aCulture.
> 650  0$aHeritage tourism.
> 650  6$aCulture$xAspect sociologique.
> 650  6$aTourisme culturel.
> 650  6$aTourisme$xAspect social.
> 650  6$aTourisme.
> 650  6$aTourisme et arts.
> 650  7$acultural tourism.$2aat
> 650  7$atourism.$2aat
> 650  7$aBUSINESS & ECONOMICS$xMarketing$xGeneral.$2bisacsh
> 650  7$aHeritage tourism.$2fast$0(OCoLC)fst00955465
> 650  7$aCulture.$2fast$0(OCoLC)fst00885059
> 650  7$aTourism.$2fast$0(OCoLC)fst01153142
> 650  7$aTourism and the arts.$2fast$0(OCoLC)fst01153221
> 650  7$aTourism$xSocial aspects.$2fast$0(OCoLC)fst01153202
> 655  4$aElectronic books.
> 776 08$iPrint version:$aLaplante, Marc.$tExpérience touristique
> contemporaine : Fondements sociaux et culturels.$dQuébec : Presses de
> l''niversite du Quebec, ©1996$z9782760509108
> 830  0$aTourisme (Presses de l'Université du Québec)
> 856 40$3desLibris$uhttps://www.deslibris.ca/ID/422431
> 856 40$3Project MUSE$uhttps://muse.jhu.edu/books/9782760521292
> 856 40$3ProQuest Ebook Central$uhttps://
> public.ebookcentral.proquest.com/choice/publicfullrecord.aspx?p=600242
> 856 40$3JSTOR$uhttps://www.jstor.org/stable/10.2307/j.ctv18pgzcc
> 880  0$6830-00/Zsym$aCollection Tourisme (Presses de l'Universit�e du
> Qu�ebec)
> 938   $aProQuest Ebook Central$bEBLB$nEBL600242
> 938   $aProject MUSE$bMUSE$nmuse20945
> 994   $aZ0$bVA@
> 948   $hHELD BY VA@ - 86 OTHER HOLDINGS
>
> LEADER 02823cam a2200721 a 4500
> 001 ocn276644602
> 003 OCoLC
> 005 20221102144112.0
> 008 081121s2008    quca     b    000 p eng
> 040
>  $aNLC$beng$cNLC$dCDX$dBWX$dSUC$dUKMGB$dOCLCF$dNLC$dOCLCA$dREB$dOCLCA$dOCLCQ$dOCLCO
> 015   $a20089424808E$2can
> 015   $a20089424808$2can
> 016   $a(AMICUS)000034543125
> 016 7 $a015299625$2Uk
> 020   $a9782920325241$q(Galerie de l'UQAM)
> 020   $a2920325248
> 020   $a9782980985249$q(Galerie Simon Blais)
> 020   $a2980985244
> 035   $a(OCoLC)276644602
> 041 0 $aeng$afre
> 043   $an-cn-qu
> 050  4$aN6549.G686$bA4 2008
> 055 02$aNB249*
> 055  3$aN6549 G686$bA4 2009
> 082 04$a730.92$222
> 084   $acci1icc$2lacc
> 100 1 $aDéry, Louise,$d1955-
> 245 10$aRêver le nouveau monde :$bune œuvre d'art public de Michel Goulet
> offerte par la ville de Montréal à la ville de Québec dans le cadre des
> célébrations du 400e anniversaire de sa fondation /$ctextes, Louise Déry
> et Michel Goulet.
> 246 1 $iAdded title page in English:$aDreaming a new world
> 260   $a[Montréal] :$bGalerie Simon Blais,$c2008.
> 300   $a69 pages :$billustrations (some color) ;$c20 cm
> 336   $atext$btxt$2rdacontent
> 337   $aunmediated$bn$2rdamedia
> 338   $avolume$bnc$2rdacarrier
> 500   $aIncludes poems.
> 500   $aTranslation: Donald Pistolesi.
> 504   $aIncludes bibliographical references (pages 68-69).
> 546   $aText in French and English.
> 550   $aCo-published by: City of Montréal and Galerie de l'UQAM.
> 600 10$aGoulet, Michel,$d1944-
> 650  0$aPublic art$zQuébec (Province)$zQuébec.
> 650  0$aSculpture, French-Canadian$zQuébec (Province)$y21st century.
> 650  5$aSculpture, French Canadian$zQuébec (Province)$y21st century.
> 650  6$aSculpture québécoise$y21e siècle.
> 600 17$aGoulet, Michel,$d1944-$2fast$0(OCoLC)fst00070599
> 650  7$aPublic art.$2fast$0(OCoLC)fst01082064
> 650  7$aSculpture, French-Canadian.$2fast$0(OCoLC)fst01895320
> 651  7$aQuébec.$2fast$0(OCoLC)fst01207316
> 651  7$aQuébec$zQuébec.$2fast$0(OCoLC)fst01206798
> 648  7$a2000-2099$2fast
> 700 1 $aGoulet, Michel,$d1944-
> 710 2 $aGalerie de l'UQAM.
> 710 2 $aGalerie Simon Blais.
> 710 1 $aMontréal (Québec)
> 856 42$3French equivalent / Équivalent français$uhttps://
> bac-lac.on.worldcat.org/oclc/276644605
> 938   $aCoutts Information Services$bCOUT$n9265731
> 029 0 $aNLC$b000034543125
> 029 0 $aNLC$b20089424808E
> 029 1 $aBWX$bR3781137
> 029 1 $aCDX$b9265731
> 029 1 $aUKMGB$b015299625
> 994   $aZ0$bVA@
> 948   $hNO HOLDINGS IN VA@ - 21 OTHER HOLDINGS
>
> ________________________________
> From: Code for Libraries <[log in to unmask]> on behalf of Dan Scott
> <[log in to unmask]>
> Sent: Tuesday, November 1, 2022 11:32 AM
> To: [log in to unmask] <[log in to unmask]>
> Subject: [CODE4LIB] Connecting to OCLC WorldCat Z39.50 servers: character
> encoding issues
>
> Hello:
>
> I'm wondering if anyone else has run into this situation with OCLC WorldCat
> Z39.50 servers. When we search Voilà (Canada's national union catalogue,
> built on WorldCat)
> <https://library-archives.canada.ca/eng/collection/basics/pages/voila.aspx
> >
> via Z39.50 for a record that is catalogued in French for ILL purposes, the
> resulting records contain corrupted characters where accented characters
> are expected. We're seeing this in Ex Libris Alma, where Voilà is an
> external search source maintained by Alma (we can't see the parameters Alma
> is using to connect).
>
> For example, searching Voilà for ISBN 9782920325241 returns a list of
> records for which the summaries display without accents. However, checking
> the MARC record itself shows that where there should be accents, there are
> instead literals in place of Unicode codepoints.
>
> The 245 for the first record returned for ISBN 9782920325241 appears as
> follows in Alma:
> 245 1 0 $$a R<U+00fd>ever le nouveau monde : $$b une <U+00fd>uvre d'art
> public de Michel Goulet offerte par la ville de Montr<U+00fd>eal <U+00fd>a
> la ville de Qu<U+00fd>ebec dans le cadre des c<U+00fd>el<U+00fd>ebrations
> du 400e anniversaire de sa fondation / $$c textes, Louise D<U+00fd>ery et
> Michel Goulet.
>
>    - Where we see R<U+00fd>ever, we should see Rèver.
>    - Where we see <U+00fd>uvre, we should see œuvre.
>    - Where we see Montr<U+00fd>eal, we should see Montréal.
>    - Where we see <U+00fd>a, we should see à.
>
> I don't *think *this is an example of a Unicode canonicalization into a
> normalized form using combining characters, as <U+00fd> is not a combining
> character. If that was the case, we would see <U+0301>e for é, <U+0300>a
> for à, etc.
>
> Instead, it looks like a case of corruption introduced by incorrect
> decoding. This can occur when the Z39.50 source uses UTF8 and the client
> interprets it as MARC8, or vice versa.
>
> That said, I have tested a few different approaches to querying Voilà using
> the yaz-client command line Z39.50 client (version 5.28.0 on Ubuntu), and
> it seems that Voilà itself might be returning the corrupted characters.
>
> For example, when I set the negotiation character set to MARC-8 (matching
> the LDR[09] of the returned record) and the display character set to UTF-8,
> the results on the screen and in the file show corruption:
>
> $ yaz-client -m testvoila.mrc
> Z> negcharset MARC-8
> Character set negotiation : MARC-8
> Z> charset
> Negotiation character set `MARC-8'
> Records in charset yes
> Charneg version 3
> Display character set is `UTF-8'
> MARC character set is `none'
> Query character set is `none'
> Z> authentication USERNAME/PASSWORD
> Authentication set to Open (USERNAME/PASSWORD)
> Z> open fsz3950.oclc.org:210/gclacConnecting...OK.
> Sent initrequest.
> Connection accepted by v3 target.
> UserInformationfield:
> {
>   OID: 1 2 840 10003 10 1000 17 1
>   {
>     ANY (len=66)
>   }
> }
> OCLC UserInformation:
> {
>   motd 'You are searching the FirstSearch 5.0 Z39.50 Server!'
>   dblist {
>     'laccat'
>   }
> }
> Options: search present delSet triggerResourceCtrl scan sort
> extendedServices namedResultSets
> Elapsed: 0.167063
> Z> find @attr 1=7 9782920325241
> Sent searchRequest.
> Received SearchResponse.
> Search was a success.
> Number of hits: 6, setno 1
> records returned: 0
> Elapsed: 0.190875
> Z> show
> Sent presentRequest (1+1). Records: 1 [laccat]
> Record type: USmarc
> 02802cam 2200685 a 4500 008 20081121s2008 quca b 000 p eng
> 015 $a 20089424808E $2 can
> 015 $a 20089424808 $2 can
> 016 $a (AMICUS)000034543125
> 016 7 $a 015299625 $2 Uk
> 020 $a 9782920325241 $q (Galerie de l'UQAM)
> 020 $a 2920325248
> 020 $a 9782980985249 $q (Galerie Simon Blais)
> 020 $a 2980985244
> 040 $a NLC $b eng $c NLC $d CDX $d BWX $d SUC $d UKMGB $d OCLCF $d NLC $d
> OCLCA $d REB $d OCLCA $d OCLCQ $d OCLCO
> 041 0 $a eng $a fre
> 043 $a n-cn-qu 050 4 $a N6549.G686 $b A4 2008
> 055 02 $a NB249*
> 055 3 $a N6549 G686 $b A4 2009
> 082 04 $a 730.92 $2 22
> 084 $a cci1icc $2 lacc
> 100 1 $a D�ery, Louise, $d 1955- 245 10 $a R�ever le nouveau monde : $b une
> �uvre d'art public de Michel Goulet offerte par la ville de Montr�eal �a la
> ville de Qu�ebec dans le cadre des c�el�ebrations du 400e anniversaire de
> sa fondation / $c textes, Louise D�ery et Michel Goulet.
>
> In the file with the downloaded record (looking at it with Vim in binary
> mode) you can see the same <fd> characters as we see in Alma for the same
> record:
>
> 02802cam 2200685 a
>
> 4500008004300000015002200043015002100065016002500086016001800111020003900129020001500168020004100183020001500224040008500239041001300324043001200337050002400349055001100373055002400384082001500408084001800423100002600441245024000467246005500707260004700762300005200809336002600861337002800887338002700915500002000942500003500962504005500997546003201052550006201084600002701146600003301173648002001206650004501226650006601271650006601337650004101403650002201444650003801466651001301504651002201517700002701539710002301566710002501589710002401614856009401638938004701732945000801779947003001787948014101817948003801958948004701996948002902043948003202072949001202104^^20081121s2008
> quca b 000 p eng ^^ ^_a20089424808E^_2can^^ ^_a20089424808^_2can^^
> ^_a(AMICUS)000034543125^^7 ^_a015299625^_2Uk^^ ^_a9782920325241^_q(Galerie
> de l'UQAM)^^ ^_a2920325248^^ ^_a9782980985249^_q(Galerie Simon Blais)^^
> ^_a2980985244^^
>
> ^_aNLC^_beng^_cNLC^_dCDX^_dBWX^_dSUC^_dUKMGB^_dOCLCF^_dNLC^_dOCLCA^_dREB^_dOCLCA^_dOCLCQ^_dOCLCO^^0
> ^_aeng^_afre^^ ^_an-cn-qu^^ 4^_aN6549.G686^_bA4 2008^^02^_aNB249*^^
> 3^_aN6549 G686^_bA4 2009^^04^_a730.92^_222^^ ^_acci1icc^_2lacc^^1
> ^_aD<fd>ery, Louise,^_d1955-^^10^_aR<fd>ever le nouveau monde :^_bune
> <fd>uvre d'art public de Michel Goulet offerte par la ville de Montr<fd>eal
> <fd>a la ville de Qu<fd>ebec dans le cadre des c<fd>el<fd>ebrations du 400e
> anniversaire de sa fondation /^_ctextes, Louise D<fd>ery et Michel Goulet.
>
> If anyone has run into this with OCLC WorldCat Z39.50 and figured out a
> solution, I would love to hear it. It would even be helpful to know if you
> have a connection to an OCLC WorldCat Z39.50 server and aren't seeing these
> kinds of problems. I know most of you probably won't have authentication
> credentials for Voilà, but the setup has to be the same for other OCLC
> WorldCat Z39.50 servers... right?
>
> In Z39.50 and character encoding madness, I remain,
> Dan
>