It seems pretty simple when you look at the filing. Just quietly change the rules whenever you see fit.
> Explanation of Responses:
> 1. Transactions reported on this Form 4 were made pursuant to trading instructions adopted by the reporting person on October 30, 2017 that are intended to comply with Rule 10b5-1(c).
> Explanation of Responses:
> 1. Transactions reported on this Form 4 were made pursuant to trading instructions adopted by the reporting person on October 30, 2017 that are intended to comply with Rule 10b5-1(c).
https://www.sec.gov/Archives/edgar/data/50863/00011276021703...
https://en.m.wikipedia.org/wiki/SEC_Rule_10b5-1