It is important to understand the difference between Tied and Linked Courses, because if courses are Tied, but are not offered in the same term and/or do not have the same teacher, they will not be scheduled.
Tied Courses are offerings that will share the same resources within the same term - the same room, block, and teacher. A common example would be Art classes where Art 1, Art 2, and Art 3 are taught by the same teacher in the same room at the same time.
Art 1 should be tied to Art 2 and Art 3 and not vice versa.
Linked Courses are offerings (other than yearlong) that are to follow an offering in the first duration can be linked on the course level. An example of this would be a one term Algebra, Part 1 class that is taught in 1st Semester would be followed by a one term Algebra, Part 2 class in 2nd Semester. Rather than focus on the resources as Tied Courses do, the Linked Courses are about the student. If a student requests a course that is linked, he or she will automatically be enrolled in the subsequently linked courses.
Only one course can be linked at a time. For example, you can Link Algebra and Algebra 1 to Algebra 2 but cannot link Algebra 2 to Algebra and Algebra 1.
If a student is enrolled in a 1st semester course that is linked to a 2nd semester course, the student won't be enrolled in the 2nd semester course until Schedule Maker is run. At this time, linking a course does not work with manual enrollment.