Comment 2 for bug 1622364

Some options I see include:

1. making all fields required (but not ever item will have an ISBN or equivalent identifier, nor do all libraries necessarily using circ modifiers)
2. disabling submit-on-enter only when focus is in the ISBN input
3. disabling submit-on-enter for the entire form, obliging the operator to mouse or tab over to the submit button

#1 seems like a non-starter, but preferences regarding #2 and #3?