Thanks Stefano. Unfortunately it's not working for me - yet :) In your post you describe commenting out lines 142-152 of C4/Heading.pm. In my Heading.pm file this would also comment out the return statement of _query_limiters. Is your _query_limiters effectively reduced to the following? sub _query_limiters { my $self = shift; my $limiters = " AND at='$self->{'auth_type'}'"; return $limiters; } When I modify _query_limiters as above and rerun link_bibs_to_authorities.pl the linking still does not occur. Are you able to show me some raw MARC showing an authority linked with a biblio? I understand basically that _9 subfields are added.., but what I am wondering is if my MARC format is somehow missing some important info (or at least our delta may provide some clues). E.g. I am trying to link the following biblio with the following authority using link_bibs_to_authorities.pl: LDR 00572nam a2200193Ia 4500 003 OPIACS 005 20110225150523.0 008 110224t20001998xx 000 0 und d 020 _a0964513331 040 _cOPIACS 100 1 _aZimmerman, Linda 245 10 _aGhosts of Rockland County _cZimmerman, Linda 250 _a2000 260 _bSpirited Books _c1998 _g2000 300 _3pamphlet 650 7 _ashanties _2OPIACS 942 _2ddc _cAU 952 _40 _xpamphlet, fine _esw _00 _912234 _bOPIACS _10 _d2011-02-24 _zindian rock, _8shanties _71 _cshanties _g1.00 _yBK _aOPIACS 999 _c12223 _d12223 000 - LEADER @ 00229nz##a2200097o##4500 003 - CONTROL NUMBER IDENTIFIER @ OPIACS 005 - DATE AND TIME OF LATEST TRANSACTION @ 20110301130115.0 008 - FIXED-LENGTH DATA ELEMENTS @ 110301000000|ge|dz||aaan|||||||||||||||c|||||d 040 ## - CATALOGING SOURCE a Original cataloging OPIACS b Language of catalogi eng c Transcribing agency OPIACS 100 ## - HEADING--PERSONAL NAME a Personal name Zimmerman, Linda Both of these records are in my database and are found in Koha. A more general question. You mention "debugging Koha". How do you go about debugging Koha? I've tried putting in debugging print statements printing to koha-error_log however I run into buffering issues(?) pretty quick and the output is not reliably.. outputted. Thanks, Pete. Volunteer with the ACS http://aandc.org/ The guy the "tired old sys admin" leans on :) -- View this message in context: http://koha.1045719.n5.nabble.com/bulk-BiblioAddsAuthorities-tp3378000p34055... Sent from the Koha - Discuss mailing list archive at Nabble.com.