Set online in 2002, Latindex Catalogo was created as a referral service specializing in editorial quality criteria applied to the evaluation of Spanish journals in Science and Technology. Those journals that are compliant with a minimum of the criteria established by Latindex are included in the catalog. Editorial features like content, editorial guidelines, and online presentation are checked. Since May 2017, online journals must have their own e-ISSN, additionally to their previously assigned print ISSN. This mandatory amendment has been added to the new list of 38 editorial quality criteria decided by a group of 4 scholars members of the Latindex network, and approved during the last Latindex technical meeting held in September 2016.