Just to be clear, these are Delta Basic Economy fares, not LA Light Fares. When the flights are all DL coded like this, you are booking DL fare filings, not partner fare filings. When DL coded, the fare classes are from DL fares classes (in this case 'E' for DL BE class), not LA fare classes. If you go to the Fare Rules link on delta.com, you will find the DL fare basis codes and fare rules (which can also be looked up on ExpertFlyer under DL fare filings for JFK-CUZ). The "Light" here just designates the LA "cabin" (not really a separate cabin, of course, on BE/Light fares) on the LA operated flights. The fares under "Delta One" heading are also DL D1 fare filiings, but the "Business/PE" showing under headings just indicates the cabin on LA flights (not LA fares).

These DL BE fares have same restrictions as any other DL international BE fares with $199 "cancel" fee to receive credit from ticket for booking another ticket. DL BE fares always have a 'B' in second to last letter of fare basis codes. DL D1 fares always have 'D' in this position. The 'X' below in fare basis code indicates the coach class used to perform dual-inventory check as all BE fares are dual-inventory fares.