I attempted to clarify the Wiki wording. It now reads:

Q: Can I buy more segments?
A: This is no longer permitted. If you want to exceed the per-continent segment limit, one option is to add a "side trip" which are additional flights that are part of the ticket but calculated and priced per their own fare; you are still limited to a maximum of 16 sectors on one ticket. Another option is to include one or more flights in the booking record that are priced and ticketed separately; since such flights are on their own ticket, they do not count against the 16 segment limit of the main ticket. Not all agents or airlines are comfortable issuing separate tickets out of one booking record, so it is easier to book in a new record, but keeping al flights in one record and issuing separate tickets is often used to increase the ease of having connections protected when there are flight delays, schedule changes, etc.