The LS-CBD-SUB part is for ordering the CBD licenses as a subscription rather than as fixed term/quantity bundles. Ordering as a subscription is more flexible and makes renewals and changes easier, but not every reseller chooses to offer subscriptions as they require more effort on the part of the reseller to set up.
Functionally speaking, the licenses you get are the same regardless of whether you choose to use a subscription or not and the pricing is designed to be basically the same for each option, though there will be some variation for particular quantities and terms.
Hope that helps.
Cheers,
Dave.
