Hello,
I came across several times that journals have special issues and also proceedings that are sometimes categorized as publication that requires ISBN. In those situations they do have difficulty publishing that publication in OJS since it is needed to put ISSN in OJS.
I would liek if OJS would have more flexible iSSN/ISBN policy in corresponding fields. Thus, the system should not check whether it is ISSN or ISBN or there will be option to choose iSSn or ISBN and write in appropriate field. Selection of ISSN/ISBN can be made by small dropdown menu besides fields for ISSN or ISBN.
Thanks