Greetings.

I would like to know if the ISSN code includes a checkdigit
as the ISBN code does, and if it is the same 11-digit scheme.

I encountered this question when I was asking a librarian if
they indexed ISSN 0362-630X.

The alternative is that the publication in question was
assigned a block of ten ISSN codes for some reason, I imagine.

Thank you for your help.

:James Salsman