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How it works
For books in your library that you added from library sources (such as the Library of Congress or Overcat), we have the original MARC record. In this case, the MARC export feature will give you back the original record for the book.
For books in your library that you added from non-library sources (such as Amazon.com, or manual additions), you have a choice: fuzzy records, or non-fuzzy records. If you choose the fuzzy option, if we have a MARC record that matches your book closely (on the basis of ISBN or other control number), we will give you the library MARC record. If you choose the non-fuzzy option, or you choose the fuzzy option but we don't have a match to give you, we will instead create a MARC record from scratch.
In both cases, your LibraryThing tag/review/ratings/collections data is added to the 9xx fields (see below for more details).
What's in a basic original MARC record
For records that we produce from scratch (either because you chose no on the fuzzy option, or because we have no record that matches), we create the following fields:
- 001, 003, 005 -- control num and cataloger info. We do not do the 007 or 008 fields. The control num is the LibraryThing book ID number. Our LOC cataloging code is "MePoLT".
- 100 -- main author
- 245 -- main title. We try to follow AACR2 standards for this.
- 260 -- publisher info. We don't have publisher place info (260$a) for non-MARC books.
Due to differences between LT's internal data format and the USMARC/AACR2 standards, at this time we cannot provide other authors, subject headings, series, call numbers, etc. when producing original MARC records. If you want those fields, you should pick the fuzzy option.
Where non-standard fields go
We add any tags you've added to the book, your review, your rating of the book and what collections you have added the book to to user-defined 9xx MARC fields.
- 920$a -- your tags, repeated subfield for multiple ones
- 921$a -- your review of the book (if any)
- 922$a -- your rating of the book on a scale of 1-10 (eg. 4.5 stars on Librarything would mean a 922$a export field of "9")
- 923$a -- your collections the book is in. Repeated if in multiple collections.
MARC records are exported in MARC21 format with UTF-8 encoding. The library records used to catalog your materials may be in a different character set (MARC8 or Latin-2), but we convert all records in the export to UTF-8.
In rare cases where the data on LibraryThing is inconsistently encoded (records from SRW sources, such as the KB, and older manually-added records) and we do not have a MARC record already, diacritics are completely stripped when producing basic original MARC records. The only other choice would be to produce a MARC record with bad encoding, or leave the record out of the export. This problem does not affect books added from libraries, Overcat, or Amazon.
What about UNIMARC and DANMARC?
To keep from producing an export file that is a mix of MARC standards (a scenario which library software is ill-equipped to handle), if you have added books from UNIMARC (some German and Portuguese sources) or DANMARC (some Danish sources), the MARC export will treat the book like we don't have a MARC record at all. If you choose the fuzzy records option, it will try to give you a USMARC record if we have one that matches. If you choose no on the fuzzy option, it will create a basic USMARC record for you.
At some future point, we may make it possible to export all your records as UNIMARC or DANMARC, or export as multiple files (all the UNIMARC records in one file, then all the USMARC ones in a separate file). We will never knowingly produce an export file that is a mixture of multiple character sets or MARC syntaxes.
For technical questions or concerns please email email@example.com.
The plain English, plain sense disclaimer
LibraryThing.com is a website designed for readers and smaller libraries looking for a low-cost library management solution. It is not a full-fledged ILS. While we have tried to make MARC export as useful as possible, if you are using LibraryThing's MARC export to move to a full-fledged ILS, you should have reasonable expectations -- we simply cannot provide the level of individual data-conversion assistance or technical sophistication that a full-fledged ILS (costing 100 or 1000 times as much as we do) would provide you. We have no control over how your new system will choose to parse our records and map the data to its proprietary built-in workflows and data model.
The legalese, in all caps for maximum dramatic effect
THE MARC EXPORT FEATURE AND THE DATA PRODUCED BY IT IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL LIBRARYTHING OR ANY OF ITS EMPLOYEES BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE MARC EXPORT FEATURE OR THE USE OR OTHER DEALINGS IN THE MARC EXPORT FEATURE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROVIDED DATA IS WITH YOU. SHOULD ANY DATA OR SERVICE PROVIDED PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT LIBRARYTHING) ASSUME THE COST OF ANY NECESSARY SERVICING, REPAIR OR CORRECTION.
THAT'S IT. We'll stop shouting.