🚀 go-pugleaf

Can anyone provide a good resource for Continuing Resources
cataloging?  I am new to cataloging, and serials versus monographs
records concept is a confusing concept.  Test preparation materials
(MCAT, ACT, SAT, etc) are a specific example.

How can I know when these items belong together on the same record?  I
believe I am seeing some that do not continue to carry an ISSN, but
most of the other information, such as title, publisher, and numbering
sequence, seem to go together.

What if an item does not have an ISSN?  Can it still be placed on a
serial record?

My predecessor cataloged these by removing the ISBN and going strictly
by ISSN.  Is this a good practice? Is this based on the premise that
all information in the record must describe all items?  When I check
other library catalogs, I see serial records with numerous ISBNs in
the record.

Has the Library of Congress issued a rule interpretation on when a new
record should be created?  I thought I read something about
significant title changes. (First five words)

Can anyone recommend a large public library that would serve as a good
example to follow and learn from?

Is there an absolute on serial records versus monographs?

Any help would be appreciated.