What version of a journal is used when the indexing process begins?
Once a journal has been approved for MEDLINE indexing, NLM acquires a subscription or license to the journal. Most journals are indexed from the online version; NLM will subscribe to and use the paper version for indexing if an electronic version is not available. License terms must not prohibit the NLM from crawling the journal web site with an automated program (web robot, crawler, spider, or similar devices) in order to cost effectively obtain some of the article metadata normally found within a MEDLINE citation record. NLM does not use the acquired information for anything other than the journal indexing process. Any data not used in the MEDLINE citation record will not be kept past the indexing processing activities. If needed, NLM will also work with the publisher to ensure that any indexing programs accessing the journal site will do so at a limited requesting speed and time period to ensure that these NLM program activities do not interfere with the journal site’s regular activ
