NISO standards state there are both "Custom Periodicals" and "Standard Periodicals" and are defined as follows:
Custom Periodicals: "Custom periodicals shall be collated in compliance with instructions from the customer. Service can include custom placement of title page, table of contents, index, supplements, and other loose pages; removal of covers and unpaginated advertisements as the front and back of each issue..."
Standard Periodicals: "Standard periodicals shall be inspected for completeness and correct order of issues. Title page, table of contents, index, supplements, and other loose pages shall be bound in the order in which they are received by the binder from the customer. Advertisements shall be left in place."