Hi Kathy,
The Harvester collects article-level metadata, but since the ISSN is journal-level metadata, it's not indexed. We've considered adding a journal-level metadata harvesting plugin and may do this in the future; this would be a minor development task.
Currently, the ISSNs specified in setup are used in the following places:
- Resolver plugin to resolve articles based on ISSN
- Counter stats plugin
- CrossRef export plugin
- Erudit export plugin
- PubMed export plugin
ISSNs are not currently exposed via the OAI interface, which is what the Harvester uses.
Regards,
Alec Smecher
Open Journal Systems Team